Rename PXE installer menu entry, add vanilla NixOS minimal netboot entry

The iPXE menu's "nixos" entry actually chain-loads this flake's own custom auto-installer image, not a stock NixOS image — rename it to "auto-installer" (label "NixOS Auto-Installer") so the menu says what it boots, and set networking.hostName on netbootSystem to match, so the generated system name (nixos-system-auto-installer-*) and staged directory (/srv/pxe/http/auto-installer) agree with the menu entry too. Add a second, genuinely vanilla NixOS minimal netboot image (netbootMinimalSystem in flake.nix — nixpkgs' netboot-minimal.nix on its own, none of modules/installer/common.nix's auto-installer wiring), built from source the same way as the auto-installer image and exposed as packages.x86_64-linux.pxe-minimal. Staged and menu-wired the same way, as "nixos-minimal" (item, hostname, and directory all matching). modules/pxe-boot/stage-installer-artifacts.nix is generalized to stage both images via a shared rule-builder instead of one hardcoded set of paths. Verified: nix eval confirms both images' config.system.name matches their menu entry/directory names, the pxe-boot host itself builds clean with the new menu.ipxe, and the new pxe-minimal image was booted directly under QEMU (kernel+initrd, no KVM) to a working login shell with hostname nixos-minimal, no hang.
Merge pull request 'Fix PXE netboot installer hanging at boot (ISO/netboot module conflict)' (#30 ) from worktree-fix-pxe-netboot-hang into main
2026-07-21 22:45:25 +00:00 · 2026-07-21 22:20:03 +00:00 · 2026-07-21 22:15:44 +00:00 · 2026-07-21 21:55:25 +00:00 · 2026-07-21 20:22:56 +00:00 · 2026-07-21 20:07:30 +00:00
95 changed files with 6060 additions and 1061 deletions
@@ -13,17 +13,17 @@ jobs:
    steps:
      - name: Check out repository
        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0

      - name: Install Nix
        uses: DeterminateSystems/nix-installer-action@v19

-      - name: Evaluate all NixOS hosts
-        run: |
-          set -euo pipefail
-          hosts="$(nix --extra-experimental-features 'nix-command flakes' eval --json \
-            .#nixosConfigurations --apply builtins.attrNames | jq -r '.[]')"
-          for host in $hosts; do
-            echo "Evaluating ${host}"
-            nix --extra-experimental-features 'nix-command flakes' eval \
-              ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath" --raw
-          done
+      # Scoped to files changed since the PR base / previous push -- see
+      # scripts/codex-maintenance.sh. CI never passes --full-check: that
+      # full sweep is for local/manual use, since it's slow enough to time
+      # out this runner.
+      - name: Run maintenance checks (secrets, fmt, lint, eval -- changed files only)
+        env:
+          MAINT_BASE_SHA: ${{ github.event.pull_request.base.sha || github.event.before }}
+        run: bash scripts/codex-maintenance.sh
@@ -13,17 +13,17 @@ jobs:
    steps:
      - name: Check out repository
        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0

      - name: Install Nix
        uses: DeterminateSystems/nix-installer-action@v19

-      - name: Evaluate all NixOS hosts
-        run: |
-          set -euo pipefail
-          hosts="$(nix --extra-experimental-features 'nix-command flakes' eval --json \
-            .#nixosConfigurations --apply builtins.attrNames | jq -r '.[]')"
-          for host in $hosts; do
-            echo "Evaluating ${host}"
-            nix --extra-experimental-features 'nix-command flakes' eval \
-              ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath" --raw
-          done
+      # Scoped to files changed since the PR base / previous push -- see
+      # scripts/codex-maintenance.sh. CI never passes --full-check: that
+      # full sweep is for local/manual use, since it's slow enough to time
+      # out this runner.
+      - name: Run maintenance checks (secrets, fmt, lint, eval -- changed files only)
+        env:
+          MAINT_BASE_SHA: ${{ github.event.pull_request.base.sha || github.event.before }}
+        run: bash scripts/codex-maintenance.sh
@@ -3,12 +3,22 @@
 result
 result-*

+# Disko's proxmox-* image-builder writes the finished .raw disk image
+# directly into the current directory, not into a result-* symlink (see
+# docs/proxmox-images.md, scripts/create-proxmox-resource.sh) — several GB
+# each, never meant to be committed.
+*.raw
+
 # Ignore automatically generated direnv output
 .direnv

-auto-installer/flake.lock
-auto-installer/result
-auto-installer/nixos-auto.iso
+# Python bytecode cache (scripts/lib/*.py)
+__pycache__/
+*.pyc
+
+# Locally-generated SSH host keys staged for transfer to a new machine
+# during install (see scripts/prepare-host-key.sh) — never commit these.
+host-keys/

 # Temporary Milestone 1 audit checklist (remove-sensetive-info-refactor.md)
 # - working notes only, never committed, deleted once every row is rotated.
@@ -1,8 +1,17 @@
 keys:
-  - &admin age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+  - &admin age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
  - &docker age19gfn2yedg76dmztm4hncr7vf3r3c9j0qpt4rap7y7gersjk4m3ks2lhd0e
  - &server age1ll6hj5ggruetgjwjfnplpn5xtq35uhlcdflksx3xmnjm6s3uad9sz70jkf
  - &nix-cache age120le4a5l8dh3lyfgvmj3d9ksmej6ajs5mer5y7r0vfg3x9fn69dqf8xgzu
+  - &nix-minimal age120whqj96g26lsgy4udvgsn8dc9lumh8jeu3a564fx79rjr5lxffqmrljuu
+  - &proxmox-minimal age10at8862478urh0eeuwh8hzln6ck78jgwtztgxatwqlzwagg77y5snm4xzg
+  - &lxc-nix-cache age1xjst4frdh0th6q8m7p7u9g5af7ty5jqeum0p6z8a52a9q7st7ewqw8yl9j
+  - &lxc-docker age1ezk9x53zt8kcnscdm80jcyf0xq97vndv7jsn3rl8cc0cwm2jmpmq372dzs
+  - &lxc-minimal age1jy444f9d9stygj4p3w9kh54cqcfr654tvr75tdvee5cxsgtdtc9q3v60ep
+  - &lxc-pxe-boot age1fxxzpnfse8nd9wz78ht3m0plrmraacf4cpga0pe8fm2tdnqcgy8q7qsyvp
+  - &lxc-gui age190htw7prp4vln076dxjx3gxxaq06h0zl0te7cqgpx79vl3lhkaes8suy05
+  - &proxmox-server age1ukpqxzl44mnjpy5r96sfuc5sqzm47u4k8ujjh5qdgy6jvl9uqgpspymqfk
+  - &vm-server age15kh7akxlx7zn00tey79rq2g8lgs4j5y77rcnyfxrxap8ckfu0a9sqvtdhh

 creation_rules:
  # Shared across every currently-deployed host: root/nixos password hash,
@@ -16,18 +25,30 @@ creation_rules:
          - *docker
          - *server
          - *nix-cache
+          - *lxc-minimal
+          - *nix-minimal
+          - *lxc-nix-cache
+          - *proxmox-minimal
+          - *lxc-docker
+          - *lxc-pxe-boot
+          - *lxc-gui
+          - *proxmox-server
+          - *vm-server

  - path_regex: secrets/nix-cache\.yaml$
    key_groups:
      - age:
          - *admin
          - *nix-cache
+          - *lxc-nix-cache

  - path_regex: secrets/server\.yaml$
    key_groups:
      - age:
          - *admin
          - *server
+          - *proxmox-server
+          - *vm-server

  - path_regex: secrets/docker\.yaml$
    key_groups:
@@ -7,7 +7,7 @@ servers and workstation.

 The flake exposes NixOS configurations named `<platform>-<buildtype>`
 (platforms: `linode`, `proxmox`, `lxc`; build types: `minimal`, `nix-cache`,
-`server`, `docker`, `gui`, `pxe-boot`), generated from `modules/platforms/*`
+`server`, `docker`, `gui`, `pxe-boot`, `tailscale-exit-node`, `tor-relay`), generated from `modules/platforms/*`
 and `modules/build-types/*` by the `mkTarget` function in `flake.nix`. Not
 every combination is built — `pxe-boot` has no `linode` variant. See
 `README.md` for the full current target list; treat `flake.nix` as the
@@ -35,9 +35,14 @@ Use these commands when validating changes:
 ```bash
 bash scripts/codex-setup.sh
 bash scripts/codex-maintenance.sh
-bash scripts/codex-maintenance.sh dry-run
 ```

+With no flags, `codex-maintenance.sh` scopes fmt-check/statix/eval to files
+changed against a base ref — this is what CI runs on every push/PR. For the
+full sweep (every host, every package — slow; CI never runs this), use
+`bash scripts/codex-maintenance.sh --full-check` (add `--dry-run` for build
+planning on top of whichever scope is active).
+
 Host evaluation is safe when limited to drvPath checks:

 ```bash
@@ -0,0 +1,150 @@
+# Flake End-to-End Audit Report
+
+**Date:** 2026-07-21
+**Scope:** Full static lint/eval sweep + live build/deploy/interrogate/destroy testing of every `lxc-*` and `proxmox-*` flake target against `pve.sweet.home`, plus an audit of the operator's ability to manage the flake/secrets tooling.
+**Branch:** `worktree-flake-e2e-audit` (this session's isolated worktree)
+
+## Executive Summary
+
+The flake itself is in good shape: `nixpkgs-fmt`, `statix`, and a full eval + dry-run build of every host and package are all clean. Every `lxc-*`/`proxmox-*` target's NixOS configuration builds successfully — no target has a broken derivation graph.
+
+The issues found are **operational, not code-level**:
+
+1. **pve.sweet.home is critically low on disk space** (91-95% full during this session) and cannot currently build the two largest closures (`gui`, `pxe-boot`) to completion — this actively blocks deploying/redeploying those hosts via the documented workflow.
+2. **A real, reproducible secrets-decryption failure** was caught live: a stale cached container image (built before a same-day sops-key fix) boots with sshd never starting and every secret failing to decrypt. This is a **general hazard in `create-proxmox-resource.sh`'s "reuse the cached image if present" default**, not a one-off.
+3. **sops key/anchor drift**: `proxmox-minimal` has a `.sops.yaml` recipient anchor with no corresponding private key anywhere in this environment; several `lxc-*`/`proxmox-*` targets have no sops registration at all yet.
+4. One concrete script bug was found and **fixed in this session**: `create-proxmox-resource.sh` never enabled the QEMU guest agent channel on VMs it creates, despite the guest OS already running it.
+5. A management-surface audit (of the operator's ability to run this repo day to day) found 5 process gaps, detailed below.
+
+Nothing here required or received a `nixos-rebuild switch/boot/test`, `nixos-install`, or any disk-formatting command — all validation was `nix build`/`nix eval`, plus disposable `pct`/`qm` create-then-destroy cycles via the repo's own `create-proxmox-resource.sh`.
+
+---
+
+## 1. Static Analysis Results — all clean
+
+`bash scripts/codex-maintenance.sh --full-check --dry-run` (whole-tree sweep, not just changed files):
+
+| Check | Result |
+|---|---|
+| Secret grep | Clean — only the documented exceptions (installer's own hashed passwords, `access-tokens` comment references) |
+| `nixpkgs-fmt --check` | 0/53 files would be reformatted |
+| `statix` | No lint warnings |
+| nix-cache host key drift check | Up to date |
+| Full eval of every host's `system.build.toplevel` | All 19 `nixosConfigurations` targets evaluate cleanly |
+| Dry-run build of every host + package | All succeed, no derivation errors |
+
+No drift, no formatting issues, no lint findings anywhere in the tree.
+
+---
+
+## 2. Per-Target Test Results
+
+Legend: **LIVE** = built on pve, `pct`/`qm` create → interrogated → destroyed. **BUILD-ONLY** = `nix build` validated the config (mostly `.config.system.build.toplevel`, occasionally `.tarball`), no resource created on pve.
+
+| Target | Test type | Result | Notes |
+|---|---|---|---|
+| `lxc-docker` | BUILD-ONLY | ✅ PASS | Live redeploy skipped — CT105 is already running this identity in production; `--allow-duplicate-host` would have destroyed it. |
+| `lxc-minimal` | **LIVE** | ✅ PASS (after retry) | First attempt reused a stale cached tarball predating a same-day sops-key commit → activation failed, sshd never started (see Finding #2). Redeployed with `--force-rebuild`: clean boot, `systemctl is-system-running` = `running`, secrets decrypted, sshd listening, users correct. |
+| `lxc-nix-cache` | BUILD-ONLY | ✅ PASS (after retry) | Live redeploy skipped — CT101 is already running this identity. First local build attempt appeared to hang on a remote-builder handoff to nix-cache; killed and retried with `--builders ""` (local-only), succeeded. |
+| `lxc-gui` | **LIVE (attempted)** | ⚠️ BLOCKED by pve disk space | Registered a fresh sops key (no prior registration existed), built successfully through the full NixOS system closure, then **failed packaging the tarball**: `No space left on device` on pve's root filesystem. Not a flake defect. |
+| `lxc-pxe-boot` | **LIVE (attempted)** | ⚠️ BLOCKED by pve disk space | Same failure as `lxc-gui` — this target additionally builds a full nested installer/netboot image (`stage-installer-artifacts.nix`), making it similarly large. Failed with the same `No space left on device` error, immediately after the gui attempt had already consumed pve's remaining headroom. |
+| `lxc-server` | BUILD-ONLY | ✅ PASS | No sops key registered yet; live deploy also would have hit `boot.zfs.extraPools` trying to import a real ZFS pool that doesn't exist in an isolated test container — an expected limitation of testing this build type outside its real hardware, not a bug. |
+| `lxc-tailscale-exit-node` | BUILD-ONLY | ✅ PASS | No sops key registered yet. |
+| `lxc-tor-relay` | BUILD-ONLY | ✅ PASS | Live redeploy skipped — CT106 already holds this identity in production. |
+| `proxmox-docker` | BUILD-ONLY | ✅ PASS (after retry) | Live redeploy skipped — both CT105 *and* VM103 already hold `docker` identities. Combined `toplevel` + `diskoImagesScript` build crashed with a **Nix-internal assertion failure** (`worker.cc:360`) under this session's memory pressure (see Finding #6) — not a flake bug. Retried with `toplevel` alone: clean. |
+| `proxmox-minimal` | **LIVE (attempted)** | ⚠️ BLOCKED by key drift → BUILD-ONLY | `.sops.yaml` has a registered `&proxmox-minimal` anchor but **no corresponding private key exists anywhere in this environment** — the script correctly refused to generate a mismatched replacement. Fell back to `toplevel` build: ✅ PASS. |
+| `proxmox-nix-cache` | BUILD-ONLY | ✅ PASS | No sops key registered yet. |
+| `proxmox-gui` | BUILD-ONLY | ⚠️ Killed after ~40min (resource-limited) | This session's local build machine has only 2GB RAM; swap filled completely (2.0/2.0GB) and the build stalled, so it was killed rather than risk destabilizing the session further. **Not a flake defect** — the equivalent `gui` NixOS configuration already proved fully buildable during the `lxc-gui` live attempt above (it built the entire system closure successfully and only failed at the pve-side tarball-packaging step due to disk space, not the config). |
+| `proxmox-pxe-boot` | BUILD-ONLY | ⚠️ Killed after ~35min (resource-limited) | Was deep into building the nested installer's kernel initrd (this build type bundles a full netboot installer image via `stage-installer-artifacts.nix`) when killed to keep the audit moving. **Not a flake defect** — this target's own module logic was already effectively validated via the earlier *live* pve deploy attempt (`lxc-pxe-boot` above), which built the complete image and only failed at the final tarball-packaging step due to pve's disk space (Finding 1). |
+| `proxmox-server` | BUILD-ONLY | ✅ PASS | No sops key registered yet; same ZFS-pool caveat as `lxc-server` would apply to a live deploy. |
+| `proxmox-tailscale-exit-node` | BUILD-ONLY | ✅ PASS | No sops key registered yet. |
+
+**Not tested at all:** `linode-*` targets (not deployable to Proxmox) and `installer` (not a normal host) — both were still covered by the static eval/dry-run-build sweep above.
+
+---
+
+## 3. Findings, Ranked by Severity
+
+### Finding 1 — pve.sweet.home is critically low on disk space (blocks real deployments)
+
+At session start: `/dev/mapper/pve-root` was **95% full, 5.3GB free** (of 94GB). After two failed large builds it recovered slightly to **91% full, 8.2GB free** (nix cleans up its own failed-build scratch space). `/nix/store` alone is 26GB; `nix-store --gc --print-dead` reports **zero** reclaimable garbage — everything currently in the store is a live GC root, so `nix-collect-garbage` won't help without first removing old roots.
+
+**Why it matters:** `create-proxmox-resource.sh` builds every VM/CT image **directly on pve**, not on a build machine and transferred over. With <10GB headroom, any closure approaching a few GB (the `gui` build type: full Cinnamon desktop + Firefox + LibreOffice + GIMP + VS Code + xrdp; the `pxe-boot` build type: nginx/atftpd *plus* an entire nested installer/netboot image) cannot currently be built there at all. Both `lxc-gui` and `lxc-pxe-boot` failed live with `No space left on device` during this audit.
+
+**Recommended action:** Expand `pve-root`'s LV, or free space by pruning old container templates in `/var/lib/vz/template/cache` (1.5GB) / old backups in `/var/lib/vz/dump` (306MB) / auditing what's pinning 26GB of `/nix/store` as live GC roots (likely `result-*` symlinks — see below). This is real production disk state; **not something this session touched or fixed** — it needs the operator's judgment on what's safe to remove.
+
+**Secondary, smaller finding:** every `create-proxmox-resource.sh` run leaves a `result-<target>` symlink in the node's repo checkout as a permanent GC root (`ls /root/nixos/result-*` on pve showed 3 from this session alone: `lxc-docker`, `lxc-minimal`, `lxc-nix-cache`). These accumulate forever and pin their entire closures in the store. Consider having the script clean up its own `result-*` link after staging the built artifact (or use a temp `--out-link` under `/tmp`), so `nix-collect-garbage` can actually reclaim old build outputs.
+
+### Finding 2 — Stale cached images can silently ship broken secrets (reproduced live)
+
+`create-proxmox-resource.sh`'s default behavior is: if the node already has `<target>.tar.xz`/`.raw` staged, **reuse it** — only `--force-rebuild` forces a fresh build. This session hit exactly the failure mode `docs/auto-installer.md` already warns about: `lxc-minimal`'s cached tarball (built 2026-07-20T15:57Z) predated a same-day sops-key fix commit (2026-07-20T17:49Z, "clean up in ailse 3"). The deployed container booted with:
+
+```
+sops-install-secrets: failed to decrypt '.../common.yaml': Error getting data key: 0 successful groups required, got 0
+Activation script snippet 'setupSecrets' failed (1)
+```
+
+— every secret permanently failed to decrypt, `sshd` never started (though the container otherwise looked "running"). This was **not a code bug**: the currently-committed `secrets/common.yaml` decrypts fine for that host's key when checked independently; the *cached artifact on pve* simply reflected an older commit's ciphertext. Redeploying with `--force-rebuild` fixed it immediately.
+
+**Why it matters:** this is silent and easy to trigger by accident — any operator who redeploys a host without remembering `--force-rebuild` after a secrets change gets a container that looks like it started (`pct start` succeeds, `pct status` = running) but is completely inaccessible.
+
+**Recommended action:** Have `create-proxmox-resource.sh` compare the cached image's build timestamp (or embed the source commit hash in the staged filename) against current HEAD, and warn (or refuse without `--force-rebuild`) if they differ — rather than silently trusting presence alone.
+
+### Finding 3 — sops key/anchor drift
+
+Two concrete instances hit live during this session:
+
+- **`proxmox-minimal`**: `.sops.yaml` already has a registered `&proxmox-minimal` age recipient, but this environment's `host-keys/` directory has no corresponding private key file. `sync-host-keys.sh` correctly refused to generate a replacement (it would silently mismatch whatever's already registered/deployed) — but this means **no environment currently has this host's private key**, unless it exists on some other machine that was never backed up here.
+- **`lxc-gui`**, and by the same logic `lxc-server`/`lxc-tailscale-exit-node`/most `proxmox-*` targets, have **no sops registration at all yet** — expected for undeployed hosts per `docs/auto-installer.md`, but this session's live-testing needed to register `lxc-gui`'s key on the fly, which immediately hit **Finding 3b**: registering a key locally does nothing for pve's build until it's pushed to `origin/main` (pve builds via `git pull`, not from this uncommitted worktree). This is exactly gap #4 the management-surface audit (below) already flagged in the abstract — this session hit it concretely.
+
+**Recommended action:** for `proxmox-minimal`, decide whether to regenerate its key (destroying old-key decrypt access, if anything still holds it) or track down wherever the original private key lives and back it up here. For the general pattern, see the management-surface audit's recommendation to pre-flight-check key registration before building.
+
+### Finding 4 — QEMU guest agent never wired up (found and fixed this session)
+
+`modules/common/configuration.nix:44` sets `services.qemuGuest.enable = true` on every host — the guest-side agent daemon is correctly enabled everywhere. But `scripts/proxmox/create-proxmox-resource.sh`'s `qm create` call never passed `--agent 1`, so **Proxmox never created the virtio-serial channel** the agent needs. Every `proxmox-*` VM this script ever created was silently missing `qm guest exec`/IP-address reporting in the Proxmox UI, despite the guest daemon actually running.
+
+**Status: fixed in this session's worktree** (`scripts/proxmox/create-proxmox-resource.sh`, `qm create` now includes `--agent enabled=1`) — see the diff, included in the PR from this session.
+
+### Finding 5 — Orphaned container on pve (CT102)
+
+`pve.sweet.home` has a stopped LXC container, **VMID 102**, with an essentially empty config (`lock: create` and nothing else — no hostname, no rootfs, no network) — the leftover of a `pct create` that started and never finished. It predates this session (not created by any of this audit's activity) and wasn't touched. **Recommend the operator confirm it's abandoned and remove it** (`pct destroy 102 --purge 1`) — left as-is it may be someone's genuine in-progress work, so it wasn't assumed safe to delete autonomously.
+
+### Finding 6 — Nix-internal crash under memory pressure (tooling, not flake)
+
+Building `proxmox-docker`'s `toplevel` and `diskoImagesScript` together crashed with a Nix-internal assertion failure (`Assertion '!awake.empty()' failed ... worker.cc:360`, a known class of bug in Nix's multi-goal build scheduler) while this session's 2GB-RAM build container was under heavy swap pressure (1.8-2.0/2GB swap in use) from a separate concurrent build. Retrying the same target alone (no concurrency) succeeded cleanly. **Not a flake defect** — purely an artifact of this session's constrained build environment; noted for completeness since it looked alarming in isolation.
+
+### Finding 7 — Management-surface audit: 5 operability gaps
+
+A focused audit of "can the operator actually run this repo day to day" (flake, home-manager, sops, related scripts) found:
+
+1. **No documented recovery path if the `&admin` sops age key is lost without a backup.** `scripts/secrets/backup-admin-key.sh` exists and works but is referenced nowhere in `README.md`/`docs/` — no forcing function ensures a backup was ever taken. `rotate-admin-key.sh` requires the *old* key to re-key; there's no bootstrap-from-nothing path documented (the real fallback — deriving an age identity from any still-live host's own SSH key — isn't written down anywhere).
+2. **home-manager has no standalone iteration path.** It's wired only inside `nixosConfigurations` (`flake.nix`) — no `homeConfigurations` output. The fastest real shortcut (`nix build .#nixosConfigurations.<target>.config.home-manager.users.nixos.home.activationPackage`) isn't documented anywhere, so the practical workflow is a full host rebuild to test one HM tweak.
+3. **Gitea's flake-lock-update workflow pushes straight to `main` with no pre-merge validation.** `.gitea/workflows/update-flake-lock.yml` commits and pushes `nix flake update`'s result directly; `codex-maintenance.sh` only runs *after*, on the resulting push — a genuinely broken lockfile bump lands on `main` before anything catches it. (The GitHub-side workflow is safer — PR-based — but has the opposite gap: nothing alerts if the PR sits unmerged.)
+4. **No pre-flight check that a build target has a registered sops key before building it.** `docs/auto-installer.md` documents the failure mode (silent, total secrets-decrypt failure) but nothing in `create-proxmox-resource.sh` refuses to proceed when it's about to build a target with no `.sops.yaml` anchor — it's on the operator to remember. This session's `lxc-gui` test hit close to this exact gap (needed the key added on the fly, mid-session).
+5. **`vars.remoteBuilderAuthorizedKeys` has the same drift risk as `vars.nixCacheHostKey`, but no checker script.** `sync-nix-cache-host-key.sh --check` guards the latter; the former (and `vars.pxeServerIp`/`vars.pbsIp`) has no equivalent — a rotated/revoked client key just silently stops working with no diagnostic pointing back here.
+
+---
+
+## 4. Action Plan (priority order)
+
+1. **Free up disk space on pve.sweet.home** (or expand `pve-root`). Blocking: `lxc-gui`, `proxmox-gui`, `lxc-pxe-boot`, `proxmox-pxe-boot` cannot currently be built/redeployed on this node at all.
+2. **Decide on `proxmox-minimal`'s orphaned sops key**: locate the original private key and back it up here, or accept regenerating it (breaks decrypt access for whoever/whatever currently holds the old one).
+3. **Merge this session's PR** (see below) to get the `--agent 1` fix and `lxc-gui`'s new sops registration onto `main` — required before `lxc-gui` can be live-redeployed with working secrets.
+4. **Add a staleness guard to `create-proxmox-resource.sh`'s cache-reuse path** (Finding 2) — highest-leverage fix, since it silently produces a broken-but-"running" host.
+5. **Add a pre-flight sops-anchor check to `create-proxmox-resource.sh`** (management-surface gap #4) — same root cause class as #4 above, catch it before building instead of at first boot.
+6. Investigate/clean up **CT102** on pve (Finding 5) — confirm abandoned, then remove.
+7. Document `backup-admin-key.sh` in `README.md`'s Security Notes and add the live-host-key bootstrap-recovery procedure to `docs/` (management-surface gap #1).
+8. Add pre-push validation to the Gitea flake-lock-update workflow (management-surface gap #3).
+9. Lower-priority: document the home-manager `activationPackage` shortcut (gap #2); extend `sync-nix-cache-host-key.sh`'s drift-check pattern to `remoteBuilderAuthorizedKeys` (gap #5).
+10. Follow-up session: finish build-validating `proxmox-gui` and `proxmox-pxe-boot` (both killed here after 35-40min on this session's 2GB-RAM machine — not failures, just unfinished) once pve has headroom (item 1) — ideally from a machine with more RAM. `proxmox-server` and `proxmox-tailscale-exit-node` already passed build-only validation in this session, no follow-up needed.
+
+---
+
+## 5. Uncommitted Changes From This Session
+
+This worktree (`worktree-flake-e2e-audit`) currently has:
+
+- `scripts/proxmox/create-proxmox-resource.sh` — the `--agent enabled=1` fix (Finding 4).
+- `.sops.yaml` / `secrets/common.yaml` — `lxc-gui`'s new age key registered as a recipient (generated live during this session's testing).
+
+Per this session's standard workflow, these will be committed, pushed, and opened as a draft PR rather than pushed to `main` directly — merging it is the operator's call, and is also **prerequisite to live-redeploying `lxc-gui` successfully** (its build will keep hitting the sops-staleness failure from Finding 2 on pve until this registration is on `origin/main`).
@@ -17,11 +17,87 @@ machines when deployed.
 - Validation is limited to evaluation, linting, formatting checks, and
  `nix build --dry-run --no-link`.
 - Do not add secrets, tokens, private keys, or new password hashes to the repo.
- This repo currently contains **committed password hashes** (e.g.
-  `prepare.sh`, `hosts/nixos/configuration.nix`) and SSH public keys (e.g.
-  `modules/nix-cache/server.nix`). The hashes are known tech debt — do not use
-  them as a template for new hosts, and flag any *new* secret-like string you
-  encounter instead of committing it.
+- This repo currently contains **committed password hashes** in
+  `modules/installer/common.nix` (the auto-installer's own root/nixos login —
+  a deliberate, documented choice, see `docs/auto-installer.md`, not
+  accidental tech debt) and **SSH public keys** in `variables.nix`
+  (`vars.adminSshKey`, `vars.remoteBuilderAuthorizedKeys`) plus a couple of
+  per-host `KEY` values for beszel-agent auth (`hosts/server/host.nix`,
+  `hosts/nix-cache/host.nix`). Don't use the installer's hardcoded hash as a
+  template for a *real* host — every other host uses sops-nix
+  (`hashedPasswordFile`, see "Security Notes" in `README.md`). Flag any *new*
+  secret-like string you encounter instead of committing it.
+- `host-keys/` is gitignored — locally-generated *private* SSH host keys for
+  the auto-installer (see `docs/auto-installer.md`). Never commit its
+  contents; if `git status` ever shows it as trackable, something is wrong.
+
+### Two Proxmox nodes: `pve1.sweet.home` (production) and `pve-test.sweet.home` (sandbox)
+
+There are two SSH-reachable Proxmox nodes on the LAN, both defined in
+`scripts/env.sh` (`PVE1_HOST` / `PVE_TEST_HOST`), individually targetable
+via `scripts/proxmox/create-proxmox-resource.sh --node <host>` or by
+overriding `PROXMOX_HOST`. `PROXMOX_HOST` itself still defaults to
+`PVE1_HOST` (production) — that default, and every other script behavior,
+is unchanged from before `pve-test` existed; the only thing new is that
+`pve-test` can now be reached at all. They are **not interchangeable** —
+one is real production infrastructure, the other exists specifically so
+there's somewhere safe to test. The restriction below is a policy for
+Claude specifically, not a change to the tooling's own default or
+anything the operator needs to opt into.
+
+#### `pve1.sweet.home` (production — off-limits to Claude)
+
+A real, live Proxmox node hosting production VMs/containers — not a
+sandbox, and not Claude's to touch by default.
+
+- **Off-limits at all times unless the operator has given explicit,
+  same-session instructions to act on this specific host.** That
+  authorization is scoped to the task it was given for — don't carry it
+  forward to unrelated later work in the same conversation, and never
+  assume it from a previous session.
+- **Read-only for existing state is always fine, authorization or not.**
+  You may SSH in (or use `pvesm`, `qm list`, `pct list`, `qm config`, `pct
+  config`, the Proxmox API, etc.) to inspect the node's config, storage,
+  and any existing VM/container — including ones this repo didn't create.
+- **Never** modify, stop, restart, delete, reconfigure, or create anything
+  on this node (`qm set`, `pct set`, `qm destroy`, `pct destroy`, `qm
+  stop`, `pct stop`, `qm create`, `pct create`, snapshot operations,
+  storage changes, etc.) — including scratch/test resources — without
+  that explicit go-ahead. Use `pve-test.sweet.home` for anything
+  exploratory instead; it exists precisely so `pve1` never has to be the
+  answer to "where do I test this."
+- **This is a Claude-specific policy, not something the scripts enforce.**
+  `scripts/env.sh`/`create-proxmox-resource.sh` default to `pve1` exactly
+  as they did before `pve-test` existed, with no extra flag or prompt
+  required — that's deliberate, so the operator's own existing workflows
+  don't change. Claude, however, must never rely on that default: every
+  Proxmox action Claude takes on its own initiative — not explicitly
+  pointed at `pve1` by the operator this session — targets `pve-test`
+  instead (e.g. `--node "$PVE_TEST_HOST"`, or `PROXMOX_HOST=$PVE_TEST_HOST`).
+  Claude's own default is `pve-test`, full stop, regardless of what the
+  tooling's own unqualified default happens to be.
+
+#### `pve-test.sweet.home` (sandbox — Claude's default target)
+
+A separate Proxmox node set aside for testing. The *tooling's* default is
+still production (`PROXMOX_HOST` → `PVE1_HOST`, see above) — but
+**Claude's own default is this node**: absent an explicit, same-session
+instruction to use `pve1`, every Proxmox action Claude initiates targets
+`pve-test`. Once targeted, it's safe to create, interrogate, and destroy
+resources on without asking first.
+
+- **Test VMs/containers are allowed, but must be torn down.** Create a
+  scratch VM or container here (e.g. via
+  `scripts/proxmox/create-proxmox-resource.sh` or raw `qm`/`pct create`)
+  to validate something. Anything created this way must be destroyed
+  again in the same session, before ending the task — never leave a test
+  resource running. Use a VMID/name that's obviously scratch (and doesn't
+  collide with a real flake target) so it's unambiguous what's safe to
+  remove.
+- **Node-level config is still not yours to change.** Creating/destroying
+  your own scratch guests is fine; Proxmox host config, storage pools, and
+  networking on `pve-test` itself are still the operator's call to make
+  manually, same as on `pve1`.

 ## Commands

@@ -29,11 +105,22 @@ machines when deployed.
 # One-time environment bootstrap (installs Nix if missing, prints hosts)
 bash scripts/codex-setup.sh

-# Full validation: secret grep, nixpkgs-fmt --check, statix lint, eval all hosts
+# Changed-files-only validation: secret grep (whole repo), nixpkgs-fmt --check
+# and statix on changed *.nix files, eval of the hosts/packages those changes
+# can affect. This is what CI runs on every push/PR.
 bash scripts/codex-maintenance.sh

-# Same, plus a dry-run build (no result symlink) of every host's toplevel
-bash scripts/codex-maintenance.sh dry-run
+# Full sweep: nixpkgs-fmt --check/statix over the whole tree, eval every host
+# and package. Slow (minutes) -- CI never runs this; use it locally before a
+# release or after touching modules/common/*, flake.nix, or variables.nix for
+# extra confidence beyond the automatic full-fallback those paths already
+# trigger in the default mode (see below).
+bash scripts/codex-maintenance.sh --full-check
+
+# Either mode, plus a dry-run build (no result symlink) of every host/package
+# in whichever scope is active
+bash scripts/codex-maintenance.sh --dry-run
+bash scripts/codex-maintenance.sh --full-check --dry-run

 # List the hosts the flake currently exposes
 nix eval --json .#nixosConfigurations --apply builtins.attrNames | jq -r '.[]'
@@ -50,58 +137,267 @@ maintenance script pulls them via `nix run github:NixOS/nixpkgs/nixos-25.11#<too
 There is no test suite — "correctness" here means the flake evaluates and
 `nixpkgs-fmt`/`statix` are clean.

+With no flags, `codex-maintenance.sh` diffs against a base ref (env
+`MAINT_BASE_SHA`, else the PR base SHA in CI, else `HEAD^` locally) and scopes
+fmt-check/statix to the changed `*.nix` files and eval to the hosts/packages
+those changes can affect — a `hosts/<name>/host.nix` edit only evals that
+host's targets, a `modules/platforms/<platform>.nix` edit only evals that
+platform's hosts, and so on. A change to `flake.nix`, `flake.lock`,
+`variables.nix`, `modules/common/*`, or any other `modules/*.nix` file outside
+`platforms/`/`build-types/` (whose blast radius isn't safely inferable from
+the path alone) falls back to evaluating every host and package, same as
+`--full-check` would, just without the whole-tree fmt/statix sweep. This
+exists because the whole-tree sweep is what was timing out CI; **CI always
+runs the plain, no-flag form and never passes `--full-check`.**
+
+The default mode's diff is against the working tree (uncommitted and staged
+edits included, not just committed ones), so it's already the right tool for
+an interactive session too: after editing one or two hosts/modules, plain
+`bash scripts/codex-maintenance.sh` naturally scopes to just what you
+touched. Reserve `--full-check` for changes that plausibly affect every host
+(`modules/common/*`, `flake.nix`, `variables.nix` — though the default mode
+already falls back to evaluating everything for those paths, `--full-check`
+additionally re-checks fmt/statix over the whole tree) or as a final check
+before committing.
+
+## Scripts
+
+Beyond `codex-setup.sh`/`codex-maintenance.sh` above, `scripts/` is
+organized by purpose: `scripts/secrets/` (sops/age + SSH host-key
+management), `scripts/proxmox/` (Proxmox deployment), `scripts/lib/`
+(shared helpers, sourced by the scripts below — not run directly), and a
+handful of repo-wide scripts left at the top level (`env.sh`,
+`bump-nixpkgs-release.sh`, plus `codex-setup.sh`/`codex-maintenance.sh`
+above). When adding a new script, put it in the matching subfolder rather
+than the top level, and if it duplicates logic another script already has,
+lift the shared part into `scripts/lib/` instead of copying it.
+
+### `scripts/secrets/`
+
+- `scripts/secrets/sync-host-keys.sh` — generates/registers SSH host keys
+  and their `.sops.yaml`/`secrets/*.yaml` recipients for flake targets,
+  idempotently (`--all`, `<target>`, `--remove`, `--regenerate-all-keys`,
+  all with `--dry-run`). The primary tool for provisioning a new host's
+  secrets access — see "Creating a new machine" in `docs/auto-installer.md`.
+- `scripts/secrets/prepare-host-key.sh` — narrower predecessor: generates a
+  key by an arbitrary name without touching `.sops.yaml`. Still useful to
+  pre-generate a key before its flake target exists yet, since
+  `sync-host-keys.sh` can only act on targets `nixosConfigurations` already
+  has.
+- `scripts/secrets/rotate-admin-key.sh <backup-admin-key> [--new-key-file
+  <path>] [--dry-run]` — rotates `.sops.yaml`'s `&admin` age key: decrypts
+  with a backed-up copy of the key currently trusted as `&admin` (verified
+  by deriving its public key and comparing, not taken on faith), replaces
+  the `&admin` line with a new key already present in the environment
+  (defaults to wherever sops/age itself would look), and runs
+  `sops updatekeys` on every `secrets/*.yaml`. One-way: the old key can no
+  longer decrypt anything re-encrypted this way. This is the automation
+  for the manual steps `sync-host-keys.sh`/`create-proxmox-resource.sh`
+  print when they bootstrap a brand-new, not-yet-trusted key on a machine
+  with no prior admin access.
+- `scripts/secrets/backup-admin-key.sh <dest-path> [--key-file <path>]
+  [--force] [--dry-run]` — copies the local sops age key (source
+  resolution matches sops/age itself: `$SOPS_AGE_KEY` inline, then
+  `--key-file`, then `$SOPS_AGE_KEY_FILE`, then the XDG default) to an
+  arbitrary destination path with `0600` permissions, validating it's a
+  real age identity and round-tripping the public key before and after the
+  write. Refuses to overwrite an existing `<dest-path>` without `--force`.
+  Purely a local filesystem copy — never touches `.sops.yaml`/
+  `secrets/*.yaml` or the repo at all. The resulting file is exactly what
+  `rotate-admin-key.sh` expects as its backup-key argument.
+- `scripts/secrets/sync-nix-cache-host-key.sh [--check] [--dry-run]
+  [--host <name>]` — detects drift between the ed25519 SSH host key
+  nix-cache is actually serving right now (via `ssh-keyscan`) and
+  `vars.nixCacheHostKey` (`variables.nix`), the value
+  `modules/nix-cache/remote-builder-client.nix` bakes into every real
+  client's declarative `programs.ssh.knownHosts` and
+  `configure-nix-cache-client.sh` hardcodes as its own default for
+  non-NixOS clients. That value has no automatic source of truth — it's
+  set once from whatever nix-cache's host key happened to be at the time,
+  and silently goes stale if the host is ever rebuilt/recreated with a new
+  key, breaking every client's distributed-build SSH trust with no error
+  that points back here. `--check` (used by `codex-maintenance.sh`, which
+  treats an unreachable nix-cache — e.g. from a non-LAN CI runner — as a
+  silent skip rather than a failure) only reports drift; the no-flags form
+  updates both files in place. Declarative clients still need a rebuild to
+  pick up the fix.
+
+### `scripts/proxmox/`
+
+- `scripts/proxmox/create-proxmox-resource.sh` — builds a `lxc-*`/
+  `proxmox-*` target's tarball/disk image and creates it on a real Proxmox
+  node (`pct create` against the tarball as a CT template / `qm create`+
+  `importdisk`), or reconfigures an existing resource's cores/memory/disk
+  size (`--modify`, always requires typing the VMID back to confirm).
+  Checks for an already-uploaded image on the node before building
+  (`--force-rebuild` to skip that and always rebuild), and probes
+  nix-cache's substituter/remote-builder reachability once up front rather
+  than letting every `nix build` call retry against it individually.
+  Refuses to create a target whose host identity already exists live on
+  the node (checked directly via `qm`/`pct`, not any file in this repo)
+  unless `--allow-duplicate-host` is passed. `--dry-run` throughout both
+  modes. The first time it has to bootstrap build tooling on a node (i.e.
+  `nix` wasn't already on its `PATH`), it also runs
+  `scripts/proxmox/configure-nix-cache-client.sh` there (non-fatally — a
+  failure just falls back to building from source / `cache.nixos.org`) so
+  the node substitutes from and can offload builds to nix-cache on every
+  subsequent run, not just this one.
+- `scripts/proxmox/configure-nix-cache-client.sh [--dry-run]
+  [--no-remote-builder] [--no-restart]` — the non-NixOS equivalent of
+  `modules/nix-cache/client.nix`/`remote-builder-client.nix`, for a plain
+  Debian machine with the Nix package manager (not NixOS) already
+  installed: run as root *on that machine* to add nix-cache as a
+  substituter in `/etc/nix/nix.conf` (`https://cache.nixos.org/` kept as
+  fallback) via `extra-substituters`/`extra-trusted-public-keys` so it
+  layers on top of whatever's already there instead of clobbering it, and,
+  if `/root/.ssh/nixremote` is already present (see docs/nix-cache.md
+  "Remote builder SSH keys"), configures it as a distributed-build
+  machine too and trusts nix-cache's SSH host key in
+  `/etc/ssh/ssh_known_hosts`. Idempotent (re-running replaces its own
+  marked block rather than duplicating it); restarts `nix-daemon` by
+  default so the change takes effect immediately.
+
+### `scripts/lib/`
+
+Sourced by the scripts above, never run directly:
+
+- `nix-bootstrap.sh` — `NIX_CONFIG`/`ensure_nix_profile`, shared by
+  `codex-setup.sh`/`codex-maintenance.sh` and the remote build commands
+  `create-proxmox-resource.sh` runs over SSH.
+- `nix-eval.sh` — `NIX_EVAL_FLAGS` plus `list_flake_targets`/
+  `flake_target_hostname` flake-introspection helpers.
+- `ssh-host-keys.sh` — `generate_host_ed25519_key`/`ssh_pubkey_to_age`,
+  shared by `sync-host-keys.sh` and `prepare-host-key.sh`.
+- `sops-age.sh` — `age_pubkey_from_identity_file`/`sops_yaml_admin_pubkey`/
+  `sops_updatekeys` plus the shared sops/age default key-file resolution,
+  shared by `backup-admin-key.sh`, `rotate-admin-key.sh`, and
+  `sync-host-keys.sh`.
+- `confirm.sh` — `confirm_typed`, the "type X back to confirm" destructive-
+  action prompt shared by `create-proxmox-resource.sh` and
+  `sync-host-keys.sh`.
+- `sync-host-keys-edit-sops.py` — the `.sops.yaml` anchor/key_groups editor
+  `sync-host-keys.sh` shells out to (see that script for why: precise,
+  idempotent YAML edits are impractical in bash).
+
+### Top level
+
+- `scripts/env.sh` — shared config (`PROXMOX_HOST`, storage pool, bridge,
+  default cores/memory) sourced by `create-proxmox-resource.sh`. Add new
+  cross-script config here instead of duplicating it per-script.
+- `scripts/bump-nixpkgs-release.sh` — bumps `flake.nix`'s `nixpkgs.url`/
+  `home-manager.url` in place. Exists because flake input URLs can't
+  reference `variables.nix` (confirmed empirically — `nix flake metadata`
+  errors on it), so this is the closest equivalent to a single source of
+  truth for the tracked release.
+
+`sync-host-keys.sh`, `create-proxmox-resource.sh`, and
+`rotate-admin-key.sh` genuinely mutate real state when run for real (not
+`--dry-run`): real `secrets/*.yaml` recipients, real Proxmox VMs/
+containers, real revocation of decrypt access. They require the
+operator's own SSH/sops access, which an agent session doesn't have — but
+don't suggest running any of them non-dry-run without the operator's
+explicit go-ahead even if it becomes technically reachable.
+`backup-admin-key.sh` only writes a key copy to a path the operator gives
+it — lower-stakes than the others, but it still handles a real private
+key, so treat its destination path choice as the operator's call too.
+
 ## Architecture

-`flake.nix` is the single entry point. It defines one `nixosConfigurations.<host>`
-attribute per machine, each built the same way:
+`flake.nix` is the single entry point. It generates one
+`nixosConfigurations.<platform>-<buildtype>` attribute per target via the
+`mkTarget` function, composed from:

 ```
 nixosSystem {
  modules = [
    disko.nixosModules.disko
-    ./hosts/<host>/configuration.nix        # host-specific config
-    ./modules/hardware-configuration/vm/<proxmox|linode>.nix
+    sops-nix.nixosModules.sops
+    ./modules/common/configuration.nix
+    ./modules/platforms/${platform}.nix        # what it runs on
+    ./modules/build-types/${buildType}.nix     # what it's for
+    hostPath                                   # hosts/<name>/host.nix — per-machine identity
    home-manager.nixosModules.home-manager { ... }
-  ];
+  ] ++ (client-only modules, for every buildType except "nix-cache" itself)
 }
 ```

-Hosts currently defined in `flake.nix`: `nixos`, `docker`, `server`,
-`nix-cache`, `nix-minimal`, `pxe-boot`, `linode-minimal`. Treat `flake.nix` as
-the source of truth for which hosts exist — `README.md`, `AGENTS.md`,
+Platforms: `linode`, `proxmox`, `lxc`. Build types: `minimal`, `nix-cache`,
+`server`, `docker`, `gui`, `pxe-boot`, `tailscale-exit-node`, `tor-relay`. Not
+every combination is built — e.g. `pxe-boot` has no `linode` variant
+(PXE/DHCP/TFTP need LAN L2 adjacency a Linode VPS doesn't have), and
+`tor-relay` currently only exists as `lxc-tor-relay`. Treat `flake.nix`'s
+`generatedTargets` as the source
+of truth for which hosts exist — `README.md`, `AGENTS.md`,
 `docs/flake-lock-automation.md`, and the CI eval workflows
 (`.github/workflows/check-nixos.yml`, `.gitea/workflows/check-nixos.yml`) list
-hosts by hand and can drift from it, so re-check them against `flake.nix` when
-adding or removing a host.
+hosts by hand (or, for the CI workflows, evaluate the flake dynamically) and
+can drift from it, so re-check them against `flake.nix` when adding or
+removing a host.

 ### Composition pattern

-Every host's real configuration lives in `hosts/<host>/configuration.nix`,
-which is a thin list of `imports` pulling in reusable pieces from `modules/`:
-
- `modules/common/configuration.nix` — base NixOS config imported by (almost)
-  every host: locale, users, nix settings, git. Nearly always the first import.
- `modules/common/home.nix` / `hosts/<host>/home.nix` — Home Manager config for
-  the `nixos` user; the `nixos` workstation has its own, other hosts share
-  `modules/common/home.nix`.
+- `hosts/<name>/host.nix` — per-machine identity **only**: hostname, hostId,
+  per-machine secrets, `system.stateVersion`. These files carry no `imports`
+  of their own beyond narrow parameterized helpers (see
+  `modules/beszel/host-token.nix` below) — all shared behavior comes from the
+  platform/build-type modules composed in `flake.nix`, not from the host file.
+- `modules/platforms/{linode,proxmox,lxc}.nix` — platform-specific config:
+  boot method, guest tooling, and (for linode/proxmox) the hypervisor-specific
+  hardware config, imported directly by the platform module itself
+  (`../hardware-configuration/vm/{proxmox,linode}.nix`) — **not** wired in
+  from `flake.nix`. `lxc.nix` has no hardware-configuration counterpart since
+  containers share the host kernel; instead it imports nixpkgs' own
+  `virtualisation/proxmox-lxc.nix`, which gives every `lxc-*` host a
+  `config.system.build.tarball` output — a plain rootfs tarball, used as a
+  `pct create ... vztmpl` CT template (**not** `pct restore`, which expects
+  `vzdump` backup-archive metadata this doesn't have), no install step —
+  see `docs/auto-installer.md`.
+- `modules/build-types/*.nix` — what a system is for:
+  minimal/server/docker/gui/pxe-boot/nix-cache/tailscale-exit-node/tor-relay.
+- `modules/common/configuration.nix` — base NixOS config imported by every
+  host: locale, users, nix settings, git.
+- `modules/common/home.nix` / `hosts/nixos/home.nix` — Home Manager config for
+  the `nixos` user; the `nixos` workstation (`gui` build type) has its own,
+  other hosts share `modules/common/home.nix`.
 - `modules/disko/proxmox.nix` — declarative disk layout (GPT: ESP + swap +
-  ext4 root) via disko, used by all Proxmox-VM hosts.
+  ext4 root) via disko, used by all Proxmox-VM hosts (`proxmox-*`, not
+  `lxc-*`). Also carries `imageSize`/`imageName`, letting every `proxmox-*`
+  host be built as a standalone, `qm importdisk`-ready `.raw` image with no
+  install step — see `docs/proxmox-images.md`.
+- `modules/disko/linode.nix` — `linode-*`'s disko config, deliberately
+  different in kind from the Proxmox one: Linode provisions and sizes
+  `/dev/sda`/`/dev/sdb` itself as whole, unpartitioned devices before the OS
+  boots, so this declares them with `destroy = false` (disko never wipes
+  them) and a bare `filesystem`/`swap` content type instead of a partition
+  table — idempotent against an already-provisioned disk, never destructive.
 - `modules/boot/efi.nix` — systemd-boot + EFI vars, paired with the disko module.
- `modules/hardware-configuration/vm/{proxmox,linode}.nix` — hypervisor-specific
-  hardware config, wired in from `flake.nix` (not from the host file).
- `modules/nix-cache/{client,server}.nix` + `modules/remote-builder-client.nix` —
-  binary cache substituter + SSH remote-builder wiring; see `docs/nix-cache.md`
-  for the full design (per-host local stores, no shared `/nix/store`, and how
-  the `nixremote` signing/SSH keys fit together).
- `modules/tailscale/`, `modules/docker/`, `modules/beszel/`,
-  `modules/services/*` — single-purpose, single-host feature modules (e.g.
-  `docker/enable-service.nix`, `services/zfs/enable-service.nix`,
-  `beszel/enable-agent.nix` for monitoring). Grep `hosts/*/configuration.nix`
-  for the `imports` list to see which modules apply to a given host.
+- `modules/installer/` — the auto-installer environment (ISO, also served as
+  PXE netboot): `common.nix` (shared config + the generated
+  `auto-install.sh`), `iso.nix`, `host-keys.nix` (optionally bakes
+  `host-keys/` into the image under `--impure`). See
+  `docs/auto-installer.md`.
+- `modules/pxe-boot/stage-installer-artifacts.nix` — builds the installer's
+  netboot image and stages it on the `pxe-boot` host so its iPXE menu can
+  chain straight to it. See `docs/pxe-boot.md`.
+- `modules/nix-cache/{client,server,remote-builder-client}.nix` — binary cache
+  substituter + SSH remote-builder wiring; see `docs/nix-cache.md` for the
+  full design (per-host local stores, no shared `/nix/store`, and how the
+  `nixremote` signing/SSH keys fit together).
+- `modules/beszel/host-token.nix` — parameterized helper module
+  (`{ name, sopsFile }`) that wires a host's beszel-agent sops secret/template
+  and `environmentFile`; used by `hosts/server/host.nix` and
+  `hosts/nix-cache/host.nix` to avoid duplicating that boilerplate.
+- `modules/tailscale/`, `modules/docker/`, `modules/networking/`,
+  `modules/traefik/`, `modules/tor/`, `modules/services/*` — single-purpose,
+  single-host
+  feature modules (e.g. `docker/enable-service.nix`,
+  `services/zfs/enable-service.nix`). Grep `modules/build-types/*.nix` for
+  each build type's `imports` list to see which modules apply where.

-New host = new `hosts/<name>/configuration.nix` + a matching block added to
-`flake.nix`'s `nixosConfigurations`, composed from existing `modules/*` pieces
-rather than duplicating config.
+New host = new `hosts/<name>/host.nix` + a matching
+`mkTarget { platform; buildType; hostPath; }` entry added to `flake.nix`'s
+`generatedTargets`, composed from existing `modules/*` pieces rather than
+duplicating config.

 ### Other docs worth reading before touching these areas

@@ -109,6 +405,12 @@ rather than duplicating config.
  handling.
 - `docs/pxe-boot.md` — the `pxe-boot` host's iPXE/TFTP/HTTP boot chain and
  directory layout under `/srv/pxe`.
+- `docs/auto-installer.md` — the installer environment (ISO/netboot/Proxmox
+  LXC), `host-keys/` and the sops-nix pre-seeding problem it solves, and why
+  `lxc-*` hosts are deliberately excluded from its menu.
+- `docs/proxmox-images.md` — building `proxmox-*` hosts as standalone `.raw`
+  disk images (disko's image builder) instead of installing, and deploying
+  the result to Proxmox.
 - `docs/flake-lock-automation.md` — how `flake.lock` updates flow through CI
  (scheduled `nix flake update` PR + host-eval-on-PR workflow) and why hosts
  should track the committed lock file rather than `nixos-rebuild --upgrade-all`.
@@ -10,22 +10,37 @@ pieces composed in `flake.nix`:

 - **Platforms** (what it runs on): `linode`, `proxmox`, `lxc`
 - **Build types** (what it's for): `minimal`, `nix-cache`, `server`, `docker`,
-  `gui`, `pxe-boot`
+  `gui`, `pxe-boot`, `tailscale-exit-node`, `tor-relay`

 Not every combination exists — `pxe-boot` has no `linode` variant, since
-PXE/DHCP/TFTP need LAN L2 adjacency that a Linode VPS doesn't have. The full
-list:
+PXE/DHCP/TFTP need LAN L2 adjacency that a Linode VPS doesn't have, and
+`tor-relay` currently only exists as `lxc-tor-relay`. The full list:

 | Target | Purpose |
 | --- | --- |
-| `linode-minimal` | Minimal NixOS host profile on a Linode VPS (real, deployed) |
-| `proxmox-minimal` | Minimal NixOS host profile on Proxmox (real, deployed — previously the flat `nix-minimal` target) |
+| `linode-minimal` | Minimal NixOS host profile on a Linode VPS |
+| `proxmox-minimal` | Minimal NixOS host profile on Proxmox — previously the flat `nix-minimal` target |
 | `lxc-minimal` | Minimal NixOS host profile in a Proxmox LXC container |
-| `linode-nix-cache` / `proxmox-nix-cache` / `lxc-nix-cache` | Local Nix binary cache and remote builder (`proxmox-nix-cache` is the real, deployed one — previously the flat `nix-cache` target) |
-| `linode-server` / `proxmox-server` / `lxc-server` | Storage, NFS, backup, and monitoring exporter host (`proxmox-server` is the real, deployed one — previously the flat `server` target) |
-| `linode-docker` / `proxmox-docker` / `lxc-docker` | Docker host for the main container stack (`proxmox-docker` is the real, deployed one — previously the flat `docker` target) |
-| `linode-gui` / `proxmox-gui` / `lxc-gui` | Cinnamon desktop workstation (`proxmox-gui` is the real, deployed one — previously the flat `nixos` target) |
-| `proxmox-pxe-boot` / `lxc-pxe-boot` | HTTP/iPXE boot asset host (`proxmox-pxe-boot` is the real, deployed one — previously the flat `pxe-boot` target) |
+| `linode-nix-cache` / `proxmox-nix-cache` / `lxc-nix-cache` | Local Nix binary cache and remote builder — previously the flat `nix-cache` target |
+| `linode-server` / `proxmox-server` / `lxc-server` | Storage, NFS, backup, and monitoring exporter host — previously the flat `server` target |
+| `linode-docker` / `proxmox-docker` / `lxc-docker` | Docker host for the main container stack — previously the flat `docker` target |
+| `linode-gui` / `proxmox-gui` / `lxc-gui` | Cinnamon desktop workstation — previously the flat `nixos` target |
+| `proxmox-pxe-boot` / `lxc-pxe-boot` | HTTP/iPXE boot asset host — previously the flat `pxe-boot` target |
+| `linode-tailscale-exit-node` / `proxmox-tailscale-exit-node` / `lxc-tailscale-exit-node` | Tailscale exit node |
+| `lxc-tor-relay` | Tor middle relay |
+
+Which variant of a given buildtype is actually deployed isn't tracked
+anywhere in this repo — that's live infrastructure state, not something a
+committed file can keep accurate, and it changes independently of the code.
+Check the Proxmox node itself, or `/etc/flake-target` on a running host (see
+below), if you need to know what's really out there right now.
+`scripts/proxmox/create-proxmox-resource.sh`'s duplicate-host guard works the same
+way: it checks the Proxmox node directly rather than any file here.
+Real, production deployments live on `pve1.sweet.home`; there's a second
+node, `pve-test.sweet.home`, set aside purely for scratch/test resources —
+see `scripts/env.sh` (`PVE1_HOST` / `PVE_TEST_HOST`, and the
+`--node`/`PROXMOX_HOST` targeting they feed into) and CLAUDE.md's Proxmox
+section for which is which.

 Each buildtype's `hosts/<name>/host.nix` carries the per-machine identity
 (hostname, hostId, per-machine secrets, `system.stateVersion`) that must stay
@@ -46,14 +61,17 @@ nix eval --json .#nixosConfigurations --apply builtins.attrNames | jq -r '.[]'
 | Path | Purpose |
 | --- | --- |
 | `flake.nix` | Flake inputs, the `mkTarget` platform × build-type generator, and `nixosConfigurations` outputs |
+| `variables.nix` | Single source of truth for shared values (LAN domain/CIDR, hostnames, timezone, primary username, storage root, NFS share subpaths/mountpoints, service ports, ...) — passed to every module and Home Manager config as the `vars` argument via `specialArgs`/`extraSpecialArgs` |
 | `hosts/<name>/host.nix` | Per-machine identity: hostname, hostId, per-machine secrets, `system.stateVersion` |
 | `hosts/nixos/home.nix` | Workstation-specific Home Manager config (used by the `gui` build type) |
 | `modules/platforms/` | Platform-specific config: virtualisation guest tools, boot method, hardware config (`linode.nix`, `proxmox.nix`, `lxc.nix`) |
 | `modules/build-types/` | Build-type-specific config: what makes a system minimal/server/docker/gui/pxe-boot/nix-cache |
 | `modules/common/` | Shared NixOS config, Home Manager, aliases imported by every host |
 | `modules/nix-cache/` | Binary cache and remote builder client/server modules |
-| `docs/` | Operational notes for cache, builders, lock updates, and boot services |
-| `scripts/` | Codex setup and validation helpers |
+| `modules/installer/` | Auto-installer environment (ISO, also served as PXE netboot) — see `docs/auto-installer.md` |
+| `host-keys/` | Gitignored, locally-generated SSH host keys for the auto-installer — see `docs/auto-installer.md` |
+| `docs/` | Operational notes for cache, builders, lock updates, boot services, the auto-installer, and Proxmox image builds |
+| `scripts/` | Codex setup, validation, host-key, release-bump, and Proxmox resource helpers |

 ## Validation

@@ -61,10 +79,19 @@ Safe validation commands for Codex and local review:

 ```bash
 bash scripts/codex-setup.sh
-bash scripts/codex-maintenance.sh dry-run
 bash scripts/codex-maintenance.sh
 ```

+`codex-maintenance.sh` with no flags (what CI runs on every push/PR) scopes
+fmt-check/statix/eval to files changed against a base ref — fast, but only
+as thorough as the diff. For the full sweep (every host, every package,
+fmt-check and statix over the whole tree — slow, CI never runs this):
+
+```bash
+bash scripts/codex-maintenance.sh --full-check
+bash scripts/codex-maintenance.sh --full-check --dry-run
+```
+
 For individual host evaluation:

 ```bash
@@ -84,6 +111,29 @@ review sessions.
  client hosts.
 - `pxe-boot` serves iPXE boot files over HTTP from `/srv/pxe`.

+### Deploying a new host
+
+Three different paths depending on target, none of them involving a manual
+`nixos-rebuild switch` from this repo:
+
+- Most hosts: boot the auto-installer, pick the target from its menu — see
+  `docs/auto-installer.md`. Every menu target has a Disko config the
+  installer formats unconditionally (`docs/auto-installer.md`'s "Storage"
+  section covers how this stays non-destructive for `linode-*`, whose disks
+  Linode itself provisions ahead of time).
+- `lxc-*` targets: not installed at all — build a ready-to-run container
+  tarball and `pct create` it as a CT template directly. `docs/auto-installer.md`
+  covers why (and the installer's menu excludes them for the same reason).
+- `proxmox-*` targets: can alternatively be built as a standalone `.raw`
+  disk image and attached to a new VM with no install step — see
+  `docs/proxmox-images.md`.
+
+`scripts/proxmox/create-proxmox-resource.sh --type lxc|vm --host <name>` automates
+either of the last two end to end (host-key registration, building the
+image directly on the Proxmox node itself, `pct create`/`qm create`), with
+`--dry-run` and a guard against duplicating an already-deployed host's
+identity. See its `--help`.
+
 ## Security Notes

 Do not commit tokens, private keys, live credentials, or new password hashes
@@ -104,6 +154,13 @@ enabled via `git config core.hooksPath .githooks`, done automatically by
 `scripts/codex-setup.sh`) runs `gitleaks protect --staged` to catch mistakes
 before they're committed.

+The auto-installer environment is the one deliberate exception to
+sops-nix-everywhere: it has a hardcoded login password instead (no stable
+per-boot host key for sops-nix to derive from on ephemeral media) — see
+"Host keys" in `docs/auto-installer.md` for why, and how the private keys it
+*does* pre-seed for target hosts stay out of git via the gitignored
+`host-keys/` directory.
+
 This repository's git *history* still contains secrets committed before this
 migration (see `remove-sensetive-info-refactor.md`) — those are being
 scrubbed and rotated separately; don't treat the repo as safe to make public
@@ -0,0 +1,290 @@
+# Auto-installer
+
+This flake builds a self-contained NixOS installer environment that can
+install any host exposed by its own `nixosConfigurations`. It was migrated
+from a formerly-separate `nix-auto-installer` repo — everything it did now
+lives here.
+
+The installer provides a small NixOS install environment (ISO, or the same
+image netbooted via PXE) with SSH access, Git support, and an interactive
+installation script.
+Logging in as any user (root or `nixos`) runs `/etc/auto-install.sh`,
+discovers available hosts from this same flake, lets the operator choose a
+target, applies that host's Disko storage configuration, installs NixOS, and
+reboots.
+
+**This applies to every `nixosConfigurations` target except `lxc-*` hosts —
+see "LXC hosts" immediately below for why those are different.**
+
+## LXC hosts
+
+`lxc-*` targets (`lxc-minimal`, `lxc-nix-cache`, `lxc-server`, `lxc-docker`,
+`lxc-gui`, `lxc-pxe-boot`, `lxc-tailscale-exit-node`, `lxc-tor-relay`) are **not** installed via `auto-install.sh` — the
+interactive menu deliberately excludes them. Don't try to select one there;
+`nixos-install` would bind-mount `/` onto `/mnt` (LXC containers have no raw
+disk to partition) and then refuse to touch the filesystem it's currently
+running on — it's designed to protect exactly this case, so it just fails.
+
+`modules/platforms/lxc.nix` imports nixpkgs' own
+`virtualisation/proxmox-lxc.nix` module, which gives every `lxc-*` host a
+`config.system.build.tarball` output — a complete, directly Proxmox-importable
+container image, no install step at all:
+
+```sh
+nix build .#nixosConfigurations.lxc-minimal.config.system.build.tarball
+```
+
+This is a plain rootfs tarball, not a `vzdump` backup archive — restoring it
+with `pct restore` fails ("archive contains no configuration file"), since
+that command expects backup-archive metadata this tarball doesn't have. Use
+it as a CT *template* instead: drop it under Proxmox's template storage
+(conventionally `/var/lib/vz/template/cache/` for the `local` storage, or
+the GUI's "Create CT" → upload-as-template flow) and create a container
+from it, supplying all config on the command line since a template has none
+of its own:
+
+```sh
+pct create <vmid> local:vztmpl/<file>.tar.xz \
+  --unprivileged 1 --features nesting=1,keyctl=1 \
+  --rootfs local-lvm:8 --hostname <name> --cores 2 --memory 2048 --swap 2048 \
+  --net0 name=eth0,bridge=vmbr0,ip=dhcp
+pct start <vmid>
+```
+
+Every one of those extra flags is load-bearing, confirmed by actually
+booting one:
+
+- `--unprivileged 1` — `modules/platforms/lxc.nix` sets
+  `proxmoxLXC.privileged = false`, so the image assumes it's running
+  unprivileged. `pct create`'s own CLI default for this flag is
+  privileged (unlike the web UI, whose checkbox defaults the other way)
+  — omit it and you get a privileged container running a NixOS config
+  that assumes unprivileged, a real mismatch.
+- `--features nesting=1,keyctl=1` — required for a modern (v247+)
+  systemd guest to boot unprivileged at all. Without it, AppArmor denies
+  the nested user namespaces and credential mounts systemd routinely
+  uses (even plain getty units) — every getty crash-loops on a denied
+  `/run/credentials/*` mount every ~3s (this is what garbage on the
+  console turns out to be) while core services like `nsncd` fail the
+  same way, and the system never finishes activating.
+- `--swap 2048` — `--memory` doesn't touch swap; it silently stays at
+  Proxmox's own 512M default otherwise. Match it to `--memory` unless
+  you deliberately want otherwise.
+
+First boot runs `boot.postBootCommands` (registers the Nix store DB and
+system profile) — there's no separate activation step to run yourself.
+`scripts/proxmox/create-proxmox-resource.sh --type lxc --host <name>` automates all
+of this (host-key handling, building the tarball directly on the Proxmox
+node itself, `pct create` with the flags above) — see its `--help`.
+
+Host keys still need pre-seeding the same way as any other host — the
+sops-nix activation-vs-first-boot race is identical regardless of how the
+image reaches the machine. Unlike the ISO/PXE installer (where
+`modules/installer/host-keys.nix` bakes *every* `host-keys/` entry into
+`/etc/host-keys/` for `auto-install.sh` to pick from and copy at install
+time — see "Host keys" below), an `lxc-*` tarball has no install step to
+copy anything during, so `modules/platforms/lxc.nix` bakes this *one*
+target's key straight into `/etc/ssh/ssh_host_ed25519_key(.pub)` directly,
+keyed by its own exact flake target name (`config.environment.etc` can't
+be read back from within a module still contributing to it, so this comes
+in via `specialArgs.flakeTarget`, set by `flake.nix`'s `mkTarget`):
+
+```sh
+NIXOS_HOST_KEYS_DIR="$(pwd)/host-keys" \
+  nix build .#nixosConfigurations.lxc-nix-cache.config.system.build.tarball --impure
+```
+
+Confirmed the hard way: without this, the tarball's own built-in system
+just generates a fresh host key at first boot like any host would, which
+can never match whatever `.sops.yaml` actually trusts for that target —
+`sops-install-secrets` fails with `Error getting data key: 0 successful
+groups required, got 0`, and *every* secret (including this host's own
+login) permanently fails to decrypt, silently — no error in the boot log
+at all, since the activation step that would install secrets only runs on
+a from-scratch first activation and skips silently once `/run/current-system`
+already exists. `scripts/proxmox/create-proxmox-resource.sh` always builds with
+`NIXOS_HOST_KEYS_DIR` set for this reason.
+
+## Layout
+
+- `modules/installer/common.nix` — shared by every installer target: SSH
+  access, users, the generated `/etc/auto-install.sh` script, and the
+  `programs.bash.loginShellInit` hook that runs it on login.
+- `modules/installer/iso.nix` — ISO/netboot-specific: imports the stock
+  `installation-cd-minimal.nix` module plus `common.nix`. Also used, paired
+  with `netboot-minimal.nix`, to build the PXE netboot variant (see
+  `docs/pxe-boot.md`).
+- `modules/installer/host-keys.nix` — optionally bakes pre-generated SSH
+  host keys into the image; see "Host keys" below.
+- `scripts/secrets/sync-host-keys.sh` — admin-workstation tool that generates,
+  registers, and (via `--remove`/`--regenerate-all-keys`) retires host
+  keys; see "Creating a New Machine" below.
+- `scripts/secrets/prepare-host-key.sh` — narrower predecessor: generates a single
+  key by an arbitrary name without touching `.sops.yaml`. Still useful for
+  pre-generating a key *before* its flake target exists (`sync-host-keys.sh`
+  can only act on targets `nixosConfigurations` already has); otherwise
+  `sync-host-keys.sh` does the same thing and more.
+
+Flake outputs:
+
+```nix
+nixosConfigurations.installer   # ISO/netboot installer image
+
+packages.x86_64-linux.iso   # installer ISO/netboot image
+packages.x86_64-linux.pxe   # netboot-ipxe + netboot-initrd + netboot-kernel, bundled
+```
+
+```sh
+nix build .#iso
+nix build .#pxe
+```
+
+There's no `nixosConfigurations.proxmox-lxc` (installer-boots-as-an-LXC-
+container) or `packages.x86_64-linux.lxc`/`.all` anymore. Both existed only
+to let the installer itself run as an LXC container so you could
+`nixos-install` some *other* host from within it — but LXC targets are
+excluded from the install menu (same bind-mount problem as any LXC
+`nixos-install`), and now have their own direct tarball path anyway (see
+"LXC hosts" above), which left the installer's own LXC form with no real
+use case.
+
+The `pxe` variant is also built automatically as part of the `pxe-boot` host
+itself (`modules/pxe-boot/stage-installer-artifacts.nix`) and served over
+iPXE as the menu's "NixOS Auto-Installer" entry — see `docs/pxe-boot.md`.
+That same host also builds and serves `packages.x86_64-linux.pxe-minimal`,
+a vanilla NixOS minimal netboot image with none of this auto-installer's
+wiring, as a separate "NixOS Minimal" menu entry — also documented in
+`docs/pxe-boot.md`, not covered further here since it's not this installer.
+
+## Host keys
+
+`sops-nix` derives each host's decryption key from its own
+`/etc/ssh/ssh_host_ed25519_key`, generated at **activation** time — before
+systemd would otherwise generate one on first boot. Without pre-seeding this
+key, secrets (including the root/nixos login password) fail to decrypt on a
+genuinely fresh install.
+
+Generated host keys live in `host-keys/` at the repo root (`ssh_host_ed25519_key`
+ `.pub` pairs per hostname). This directory is **gitignored on purpose** —
+private key material must never be committed — which also means flakes can't
+see it through a normal relative path. `modules/installer/host-keys.nix`
+reads it through `builtins.getEnv`, which Nix silently returns as an empty
+string under normal (non-`--impure`) evaluation, so the module is a no-op —
+safe by default, including in CI — unless explicitly opted into:
+
+```sh
+NIXOS_HOST_KEYS_DIR="$(pwd)/host-keys" nix build .#iso --impure
+```
+
+When built this way, every key currently in `host-keys/` is baked into the
+image at `/etc/host-keys/<hostname>_ssh_host_ed25519_key(.pub)`, and
+`auto-install.sh` automatically installs whichever one matches the flake
+target selected at install time — no manual per-host scp step needed.
+
+**Trade-off, accepted deliberately for this LAN-only setup:** baking keys in
+means every key present in `host-keys/` at build time becomes readable by
+anyone who can reach the built image — including, for the PXE variant, anyone
+who can reach the `pxe-boot` host's unauthenticated HTTP server. This is
+considered acceptable here because `pxe-boot` sits behind LAN-only network
+infrastructure, not the open internet. If that ever changes, reconsider this
+default.
+
+`auto-install.sh` still supports the older manual path as a fallback: if a
+host's key isn't baked in (`/etc/host-keys`), it checks `/root/host-keys`
+next, where you can `scp` a key in after boot, same as before this migration.
+
+## Storage
+
+Disk partitioning is handled by Disko — the installer has no hardcoded
+`parted`/`mkfs`/`mkswap`/`mount` commands, and `auto-install.sh` runs
+`disko --mode destroy,format,mount` unconditionally, no branching on whether
+the target has a Disko config. Every host reachable through this menu has
+one:
+
+- `proxmox-*` (`modules/disko/proxmox.nix`): a real GPT partition table
+  (ESP + swap + root) on `/dev/sda`.
+- `linode-*` (`modules/disko/linode.nix`): Linode provisions and sizes
+  `/dev/sda`/`/dev/sdb` itself as whole, unpartitioned block devices before
+  the OS ever boots, so this declares them with `destroy = false` (skips
+  disko's wipe stage for these disks entirely — see the option's own docs)
+  and a bare `filesystem`/`swap` content type with no partition table, and
+  the format step it does run only calls `mkfs`/`mkswap` if `blkid` shows
+  the device isn't already formatted — a re-run against an
+  already-provisioned Linode disk is a no-op, not a wipe.
+
+`lxc-*` is the only category without one — it's excluded from this menu
+entirely (see "LXC hosts" above), so it never reaches this code path.
+
+## Installer process
+
+`/etc/auto-install.sh`:
+
+1. Queries `nixosConfigurations` from this flake over the network (`git+https://<lanDomain>/beatzaplenty/nixos.git`) — this happens at *install* time, not build time, so a generic installer image always sees whatever hosts are currently committed, without needing a rebuild.
+2. Presents them as a menu; confirms the choice.
+3. Skips the `nix-cache` substituter when installing a `nix-cache` host itself (consistent with that host's own runtime config).
+4. Runs `disko --mode destroy,format,mount` (see "Storage" above — every host reachable through this menu has a Disko config, so this is unconditional).
+5. Installs the target's SSH host key from `/etc/host-keys` or `/root/host-keys` (see "Host keys" above).
+6. Runs `nixos-install --flake <url>#<choice> --no-root-password`.
+7. Cleans up and reboots.
+
+## Creating a new machine
+
+Do this instead of jumping straight to a plain install whenever the target
+host consumes any sops-nix secret — as of this writing, that's every host
+(`modules/common/configuration.nix` puts the root/nixos password hash and the
+GitHub token behind sops-nix for all of them).
+
+1. **Add the flake target** — `hosts/<name>/host.nix` plus the matching
+   `mkTarget { ... }` entry in `flake.nix`'s `generatedTargets` (see
+   "Composition pattern" in `CLAUDE.md`). No secrets involved yet, so this
+   is safe to commit on its own if you want a clean history.
+
+2. **On your admin workstation, generate and register its host key:**
+
+   ```sh
+   ./scripts/secrets/sync-host-keys.sh <flake-target>
+   ```
+
+   This generates `host-keys/<flake-target>_ssh_host_ed25519_key(.pub)`,
+   adds it as a new `.sops.yaml` anchor, works out which `secrets/*.yaml`
+   files this specific host actually references (from its own
+   `config.sops.secrets`, not guessed), adds it to each one's
+   `key_groups`, and re-encrypts them with `sops updatekeys` — no manual
+   YAML editing. Safe to re-run; it only fills in what's missing.
+
+   Doing this for every host that needs one at once — after adding several
+   new targets, or just to catch up any that were missed — is
+   `./scripts/secrets/sync-host-keys.sh --all`. See `scripts/secrets/sync-host-keys.sh --help`
+   for its other modes (`--remove`, `--regenerate-all-keys`).
+
+3. **Commit and push.** The flake build the installer uses has to see the
+   new recipient before you install, or decryption fails on first boot
+   regardless of the next step.
+
+4. **Build the installer image with keys baked in** (or reuse an already-serving `pxe-boot` host, which does this automatically once redeployed):
+
+   ```sh
+   NIXOS_HOST_KEYS_DIR="$(pwd)/host-keys" nix build .#iso --impure
+   ```
+
+5. **Boot it on the target machine**, log in, select the new host's flake
+   target from the menu, confirm. `auto-install.sh` finds the baked-in key,
+   runs Disko + `nixos-install`, and reboots.
+
+6. **Verify after reboot:**
+
+   ```sh
+   ssh <new-host> ls /run/secrets/
+   ```
+
+   If that's empty or login fails, the host's age key most likely wasn't in
+   `.sops.yaml` (or wasn't re-encrypted into the secrets file it needs) when
+   `nixos-install` ran — fix `.sops.yaml`/`secrets/*.yaml`, push, then re-run
+   `nixos-install --flake .#<hostname> --no-root-password` from a rescue
+   environment against the existing `/mnt`, or just redo the install.
+
+## Safety
+
+This installer is destructive: `disko --mode destroy,format,mount` erases
+any disk defined by the selected host's Disko configuration. Always verify
+the selected host profile and target machine before confirming.
@@ -8,9 +8,14 @@ and to verify that declared NixOS hosts still evaluate after dependency updates.
 - A scheduled workflow runs `nix flake update` once per week.
 - On GitHub, any resulting `flake.lock` change is proposed through a pull request.
 - On Gitea, the workflow can commit and push `flake.lock` directly when PR automation is not configured.
- A separate CI workflow evaluates every configured host before merge, listed
-  dynamically via `nix eval --json .#nixosConfigurations --apply builtins.attrNames`
-  rather than hand-enumerated, so it can't drift as `<platform>-<buildtype>`
+- A separate CI workflow runs `scripts/codex-maintenance.sh` before merge.
+  Its default mode scopes eval to the hosts/packages a change can affect,
+  determined from a git diff against the PR base — but a `flake.lock` change
+  is treated as repo-wide and always falls back to evaluating every host, so
+  a lock-file update PR still gets full coverage. Hosts are still listed
+  dynamically via
+  `nix eval --json .#nixosConfigurations --apply builtins.attrNames` rather
+  than hand-enumerated, so that fallback can't drift as `<platform>-<buildtype>`
  targets are added or removed. See `README.md` for the current target list.

 ## Why hosts should stop using `--upgrade-all`
@@ -8,37 +8,73 @@ This repository configures `nix-cache` as a **binary cache server** and a **remo
 - Every machine still keeps and uses its own local `/nix/store`.
 - Clients prefer `http://nix-cache` for substitutes and keep `https://cache.nixos.org/` as fallback.
 - Clients can offload builds to `nix-cache` through SSH (`nix.distributedBuilds`).
- Client hosts import `modules/nix/cache-client.nix` and, when remote building is enabled, `modules/nix/remote-builder-client.nix`.
- The `nix-cache` host imports `modules/nix/cache-server.nix`.
+- Client hosts import `modules/nix-cache/client.nix` and, when remote building is enabled, `modules/nix-cache/remote-builder-client.nix`.
+- The `nix-cache` host imports `modules/nix-cache/server.nix`.

-## Binary cache signing keys (on nix-cache)
+## Binary cache signing key
+
+`modules/nix-cache/client.nix` hardcodes every client's trust in one
+specific public key (`cache.local-1:usoWYanY3Kpq2+kDIS2nhWoLZiRxanmdysdzqCFBHW4=`).
+That means whichever host is currently playing the `nix-cache` role has to
+use that *exact* keypair — not a freshly generated one — or no client will
+accept substitutes from it (they'd just silently fall back to building
+from source). So unlike most per-host secrets, this one can't be
+self-generated on first boot; it's managed via sops-nix like every other
+secret in this repo, sourced from `secrets/nix-cache.yaml`'s
+`cache-priv-key` entry (`modules/nix-cache/server.nix`).
+
+**Adding or rotating the value:**

 ```bash
-sudo install -d -m 0700 /etc/nix
-sudo nix-store --generate-binary-cache-key nix-cache-1   /etc/nix/cache-priv.pem   /etc/nix/cache-pub.pem
-sudo chmod 0600 /etc/nix/cache-priv.pem
-sudo chmod 0644 /etc/nix/cache-pub.pem
-cat /etc/nix/cache-pub.pem
+nix-shell -p sops --run 'sops secrets/nix-cache.yaml'
 ```

-Do not commit private keys.
-Do not commit new password hashes or live credentials. Existing committed hashes
-should be rotated and moved to host-local secret management.
+Add (or replace) a `cache-priv-key` entry with the private key file's exact
+contents. If you don't have it yet, generate a keypair once:
+
+```bash
+nix-store --generate-binary-cache-key nix-cache-1 cache-priv.pem cache-pub.pem
+```
+
+— paste `cache-priv.pem`'s contents into the `cache-priv-key` entry above,
+delete both local files afterward, and update
+`trusted-public-keys` in `modules/nix-cache/client.nix` (and every already-built
+client) to match `cache-pub.pem` if this is a genuine rotation rather than
+a first-time bootstrap. Any `nixos-configurations.*-nix-cache` host picks
+the new key up automatically on next activation — no more manual
+`/etc/nix/cache-priv.pem` install step.

 ## Remote builder SSH keys

-On each client, install the private key used to authenticate as `nixremote`:
+Each client authenticates as `nixremote` using its **own default root SSH
+identity** (`/root/.ssh/id_ed25519`) — not a separately-named or shared
+keypair. If a client doesn't have one yet:

 ```bash
-sudo install -d -m 0700 /root/.ssh
-sudo install -m 0600 ./nixremote /root/.ssh/nixremote
-sudo ssh -i /root/.ssh/nixremote nixremote@nix-cache nix-store --version
+sudo ssh-keygen -t ed25519 -N '' -f /root/.ssh/id_ed25519
 ```

-On `nix-cache`, install the matching public key used by `nixremote` authorized keys.
+Then add its `.pub` contents as a new entry in `vars.remoteBuilderAuthorizedKeys`
+(`variables.nix`) and rebuild `nix-cache` to pick it up (that list is
+declarative — an imperative `ssh-copy-id nixremote@nix-cache` won't stick;
+it gets overwritten on every rebuild). Verify with:

-The committed `nixremote` authorized keys are public SSH keys only. Keep the
-matching private keys on client hosts and out of the repository.
+```bash
+sudo ssh -i /root/.ssh/id_ed25519 nixremote@nix-cache nix-store --version
+```
+
+The committed `remoteBuilderAuthorizedKeys` entries are public SSH keys
+only. Keep the matching private keys on client hosts and out of the
+repository.
+
+nix-cache's own SSH *host* key is trusted declaratively via
+`programs.ssh.knownHosts` in `modules/nix-cache/remote-builder-client.nix`,
+sourced from `vars.nixCacheHostKey` (`variables.nix`) — every client rebuild
+picks it up automatically, so distributed builds don't fail with "Host key
+verification failed" on a client that has never manually SSH'd to nix-cache
+before. If nix-cache's host key is ever rotated or the host rebuilt from
+scratch, update `vars.nixCacheHostKey` to match its new
+`/etc/ssh/ssh_host_ed25519_key.pub`.

 ## Manual verification

@@ -48,8 +84,8 @@ After deployment:
 curl http://nix-cache/nix-cache-info
 nix store ping --store http://nix-cache
 nix show-config | grep -E 'substituters|trusted-public-keys|builders-use-substitutes'
-sudo ssh -i /root/.ssh/nixremote nixremote@nix-cache nix-store --version
-nix build nixpkgs#hello --builders 'ssh://nixremote@nix-cache x86_64-linux /root/.ssh/nixremote 4 2 big-parallel,kvm,nixos-test,benchmark' -L
+sudo ssh -i /root/.ssh/id_ed25519 nixremote@nix-cache nix-store --version
+nix build nixpkgs#hello --builders 'ssh://nixremote@nix-cache x86_64-linux /root/.ssh/id_ed25519 4 2 big-parallel,kvm,nixos-test,benchmark' -L
 nix path-info -r nixpkgs#hello
 curl -I "http://nix-cache/$(basename "$(nix path-info nixpkgs#hello)").narinfo"
 ```
@@ -0,0 +1,116 @@
+# Proxmox VM disk images
+
+`proxmox-*` hosts (VM platform, not `lxc-*`) can be built as standalone,
+ready-to-attach `.raw` disk images via disko's own image-builder — no
+`nixos-install`, no live installer boot. This uses the same `disko.devices`
+config (`modules/disko/proxmox.nix`) already used to format a real disk on
+install, so there's nothing host-specific to write; it's available for every
+`proxmox-*` target automatically.
+
+`scripts/proxmox/create-proxmox-resource.sh --type vm --host <name>` automates the
+whole walkthrough below (and the equivalent LXC one) end to end, including
+host-key handling and building the image directly on the Proxmox node
+itself (no local build, no image transfer) — see its `--help`. The steps
+here are what it runs under the hood, useful for doing any of it by hand
+or understanding what it does before you trust it against real
+infrastructure.
+
+## Building
+
+```sh
+nix build .#nixosConfigurations.proxmox-server.config.system.build.diskoImagesScript
+sudo ./result --build-memory 2048
+```
+
+This produces `<hostname>.raw` in the current directory (e.g. `server.raw`
+for `proxmox-server`, matching `networking.hostName`, not the flake attribute
+name — every `proxmox-*` host gets a distinctly named image instead of all
+of them producing an identical `main.raw`). The script builds inside a
+temporary QEMU VM and moves the finished image out to the working directory
+when done; `--build-memory` controls how much RAM that build VM gets.
+
+`disko.devices.disk.main.imageSize` (currently `20G`, in
+`modules/disko/proxmox.nix`) sets the image's total size — disko doesn't
+support auto-resizing, so this needs to comfortably fit ESP + swap + root at
+build time. Grow the virtual disk (and resize the filesystem) in Proxmox
+after attaching if a host needs more than that; this is the normal way to
+size these images, not a one-time decision to get exactly right up front.
+
+## Host keys
+
+The disko image script runs a real activation pass inside its temporary
+build VM while constructing the image — the same sops-nix
+activation-before-first-boot problem the installer and LXC tarball workflows
+have (see `docs/auto-installer.md`) applies here too, unmodified. Disko has
+a native mechanism for it:
+
+```sh
+sudo ./result \
+  --pre-format-files host-keys/server_ssh_host_ed25519_key /etc/ssh/ssh_host_ed25519_key \
+  --pre-format-files host-keys/server_ssh_host_ed25519_key.pub /etc/ssh/ssh_host_ed25519_key.pub \
+  --build-memory 2048
+```
+
+Generate the key first with `scripts/secrets/sync-host-keys.sh <hostname>`, same
+as any other host — see `docs/auto-installer.md` for the full walkthrough
+(it registers the new key in `.sops.yaml` and re-encrypts the affected
+`secrets/*.yaml` files too, no manual editing needed).
+
+## Deploying to Proxmox
+
+The image needs **UEFI (OVMF)**, not Proxmox's default SeaBIOS —
+`modules/boot/efi.nix` uses `systemd-boot`, which only works with UEFI
+firmware. `virtio-scsi` is safe to use as the disk bus:
+`hardware-configuration/vm/proxmox.nix` already includes `virtio_scsi` in
+its initrd kernel modules.
+
+1. Copy the image to the Proxmox host:
+
+   ```sh
+   scp server.raw root@<proxmox-host>:/var/lib/vz/import/
+   ```
+
+2. Create an empty VM shell (no disk yet) — replace `<vmid>` with a free ID
+   and `<storage>` with your storage pool's name (`pvesm status` or
+   Datacenter → Storage in the web UI):
+
+   ```sh
+   qm create <vmid> --name proxmox-server --memory 2048 --cores 2 \
+     --net0 virtio,bridge=vmbr0 \
+     --bios ovmf --machine q35 \
+     --scsihw virtio-scsi-pci \
+     --efidisk0 <storage>:1,efitype=4m,pre-enrolled-keys=0
+   ```
+
+   (`--efidisk0` is required for UEFI — it's where OVMF persists boot-entry
+   NVRAM; without it, systemd-boot's boot entry may not survive a reboot.)
+
+3. Import the raw disk into storage:
+
+   ```sh
+   qm importdisk <vmid> /var/lib/vz/import/server.raw <storage>
+   ```
+
+   This prints the resulting disk identifier (e.g. `vm-<vmid>-disk-1`).
+
+4. Attach it and set it as the boot disk:
+
+   ```sh
+   qm set <vmid> --scsi0 <storage>:vm-<vmid>-disk-1
+   qm set <vmid> --boot order=scsi0
+   ```
+
+5. Boot it:
+
+   ```sh
+   qm start <vmid>
+   ```
+
+No install step — it boots straight into the already-activated system.
+
+## Why not `nix build .#nixosConfigurations.<host>.config.system.build.vm`?
+
+That's a different, unrelated feature — `system.build.vm` (`nixos-rebuild
+build-vm`) produces an ephemeral QEMU script for locally testing a
+configuration, not a distributable disk image. It's not part of this
+workflow.
@@ -1,6 +1,10 @@
 # pxe-boot

-The `pxe-boot` host serves HTTP boot assets for iPXE clients.
+The `pxe-boot` host serves HTTP boot assets for iPXE clients — including
+self-staged copies of both this flake's own auto-installer netboot image
+(see `docs/auto-installer.md` for what that image actually is and does once
+booted) and a vanilla, unmodified NixOS minimal netboot image for plain
+rescue/inspection use.

 ## Host Role

@@ -25,7 +29,8 @@ The host creates these directories with systemd tmpfiles:
 /srv/pxe
 /srv/pxe/http
 /srv/pxe/http/images
-/srv/pxe/http/nixos
+/srv/pxe/http/auto-installer
+/srv/pxe/http/nixos-minimal
 /srv/pxe/http/systemrescue
 /srv/pxe/http/ubuntu
 /srv/pxe/http/rescue
@@ -34,7 +39,7 @@ The host creates these directories with systemd tmpfiles:

 Mount shared image storage under `/srv/pxe/http`, preferably
 `/srv/pxe/http/images` unless a menu entry expects files in a specific
-directory such as `/srv/pxe/http/nixos`.
+directory such as `/srv/pxe/http/auto-installer`.

 The HTTP iPXE chain is:

@@ -47,13 +52,37 @@ undionly.kpxe or ipxe.efi

 The generated menu currently exposes entries for:

- NixOS installer
+- NixOS Auto-Installer
+- NixOS Minimal
 - SystemRescue environment
 - iPXE shell
 - Reboot

-Kernel and initrd artifacts for the NixOS installer entry must be placed under
-`/srv/pxe/http/nixos` by an operator or a separate build process.
+Both NixOS entries chain-load a `netboot.ipxe` staged into their own
+directory (`/srv/pxe/http/auto-installer/netboot.ipxe` and
+`/srv/pxe/http/nixos-minimal/netboot.ipxe`), each nixpkgs' own generated
+netboot iPXE script (correct `init=`/`initrd=` kernel parameters included)
+rather than a hand-rolled boot line — that script in turn expects its
+kernel/initrd siblings in the same directory. Each directory's three files
+(`bzImage`, `initrd`, `netboot.ipxe`) are built from source and staged
+automatically by `modules/pxe-boot/stage-installer-artifacts.nix` via
+`systemd.tmpfiles.rules` — no manual operator step required:
+
+- `auto-installer` is this flake's own `netbootSystem` (`flake.nix`) — the
+  same auto-installer image `nix build .#pxe` produces. See
+  `docs/auto-installer.md`.
+- `nixos-minimal` is `netbootMinimalSystem` (`flake.nix`) — nixpkgs'
+  `netboot-minimal.nix` composed on its own, with none of this flake's
+  auto-installer wiring (no `common.nix`, no `auto-install.sh`, no baked
+  host keys or custom users). Same `nix build .#pxe-minimal` mechanism as
+  the auto-installer image, just a different module composition. Useful
+  as a plain rescue/inspection shell that doesn't assume anything about
+  this flake.
+
+Both images set `networking.hostName` to match their menu entry/staged
+directory name (`auto-installer` / `nixos-minimal`), so each one's
+generated system name (`nixos-system-<name>-*`) is self-describing rather
+than the nixpkgs default of `nixos-system-nixos-*` for both.

 The SystemRescue entry expects the source ISO at:

@@ -76,7 +105,7 @@ uses `archiso_http_srv` to fetch the squashfs payload over HTTP.
 Safe evaluation check:

 ```bash
-nix eval .#nixosConfigurations.pxe-boot.config.system.build.toplevel.drvPath --raw
+nix eval .#nixosConfigurations.proxmox-pxe-boot.config.system.build.toplevel.drvPath --raw
 ```

 After deployment by an operator, basic service checks are:
@@ -1,143 +0,0 @@
-# Spec: Refactor Flake Targets into Platform × Build-Type Matrix
-
-## Context
-
-The flake at `~/nixos` currently defines these output targets (flat, ad-hoc naming):
-
- `docker`
- `linode-minimal`
- `nix-cache`
- `nix-minimal`
- `nixos`
- `server`
- `pxe-boot`
-
-Some already follow a `platform-buildtype` convention (`linode-minimal`), most don't.
-`~/nix-auto-installer` is a related repo and should be checked for any coupling to
-these target names (scripts, docs, CI, or install automation that reference them by
-name) before renaming anything.
-
-## Goal
-
-Restructure the flake so targets are generated from two orthogonal concepts:
-
-**Build types** (what the system is for):
- `minimal`
- `nix-cache`
- `server`
- `docker`
- `pxe-boot`
- `gui`
-
-**Platforms** (what it's deployed on):
- `linode` (Linode VM)
- `proxmox` (Proxmox VM)
- `lxc` (Proxmox LXC container)
-
-Final targets should be named consistently as `<platform>-<buildtype>`, e.g.:
-
-```
-linode-minimal    proxmox-minimal    lxc-minimal
-linode-nix-cache  proxmox-nix-cache  lxc-nix-cache
-linode-server     proxmox-server     lxc-server
-linode-docker     proxmox-docker     lxc-docker
-linode-pxe-boot   proxmox-pxe-boot   lxc-pxe-boot
-linode-gui        proxmox-gui        lxc-gui
-```
-
-That's the full matrix (18 targets) if every build type applies to every platform.
-See **Open Questions** below — some combinations may not make sense and should be
-confirmed with me before being built out, not silently included or dropped.
-
-## Migration mapping (old → new)
-
-| Old target        | New target                                          | Notes |
-|--------------------|------------------------------------------------------|-------|
-| `linode-minimal`   | `linode-minimal`                                      | Already correct, keep as-is |
-| `nix-minimal`      | likely `proxmox-minimal` or a platform-less base module | Ambiguous — see Open Questions |
-| `nix-cache`        | base module consumed by `linode-nix-cache`, `proxmox-nix-cache`, `lxc-nix-cache` | Currently platform-less; needs to become a build-type module, not a standalone target |
-| `server`           | base module consumed by `linode-server`, `proxmox-server`, `lxc-server` | Same as above |
-| `docker`           | base module consumed by `linode-docker`, `proxmox-docker`, `lxc-docker` | Confirm docker actually makes sense as an LXC/VM guest build vs. a standalone container image — see Open Questions |
-| `pxe-boot`         | TBD — may stay a single target rather than a per-platform one | See Open Questions |
-| `nixos`            | TBD — unclear what this maps to in the new scheme | See Open Questions |
-
-## Open Questions (Claude Code: raise these with me before implementing, don't guess)
-
-1. **`nixos` target** — what is this currently used for (bare metal install, dev
-   shell, template)? It doesn't obviously map to any of the six build types.
-2. **`nix-minimal` vs `linode-minimal`** — are these two different things, or is
-   `nix-minimal` a leftover/duplicate?
-3. **`pxe-boot` and `gui` across all three platforms** — does PXE boot make sense
-   for an LXC container or a cloud VM (Linode), or is it inherently bare-metal/
-   network-boot only and should remain a single non-platform target? Does `gui`
-   make sense inside an LXC container?
-4. **`docker` as a build type** — is this "a NixOS host configured to run Docker"
-   (which would sensibly have linode/proxmox/lxc variants), or "a Docker container
-   image built by the flake" (which wouldn't take a platform prefix at all, since
-   it doesn't run on Linode/Proxmox/LXC as a guest OS)? These are structurally
-   different and change how it should be wired in.
-5. Confirm whether all 18 combinations should actually exist, or whether this is
-   meant to produce only the combinations that are genuinely useful (e.g. maybe no
-   one needs `lxc-pxe-boot`).
-
-## Implementation approach
-
-1. **Inventory first.** Read the current `flake.nix` and any `nixosConfigurations`/
-   `modules` structure. Map every existing target to what module(s) it actually
-   pulls in. Don't assume — confirm against the real file contents.
-2. **Separate build-type and platform into their own module directories**, e.g.:
-   ```
-   modules/build-types/minimal.nix
-   modules/build-types/nix-cache.nix
-   modules/build-types/server.nix
-   modules/build-types/docker.nix
-   modules/build-types/pxe-boot.nix
-   modules/build-types/gui.nix
-
-   modules/platforms/linode.nix
-   modules/platforms/proxmox.nix
-   modules/platforms/lxc.nix
-   ```
-   Build-type modules should contain only what makes a system "minimal" vs
-   "server" vs "gui", etc. Platform modules should contain only what's specific
-   to running as a Linode VM vs Proxmox VM vs LXC container (virtualisation
-   guest tools, boot method, filesystem/image format, LXC-specific constraints
-   like no kernel modules, etc).
-3. **Generate the target matrix programmatically** in `flake.nix` rather than
-   hand-writing 18 near-identical `nixosConfigurations` entries — e.g. a small
-   function that takes a platform name and build-type name, composes the two
-   modules plus any shared base module, and produces the named output. This
-   keeps future build types/platforms a one-line addition rather than a copy-paste
-   job.
-4. **Only build combinations we've confirmed make sense** (see Open Questions) —
-   don't emit all 18 by default if some are structurally invalid.
-5. **Preserve existing working configs during the transition.** Don't delete the
-   old target names until their replacements build successfully — rename/alias
-   at the end, not the start, so there's no window where the flake is broken.
-
-## Verification
-
-For every new target produced:
-```bash
-nix flake check
-nix build .#nixosConfigurations.<target>.config.system.build.toplevel
-```
-Confirm each builds without evaluation errors before considering it done. If a
-target fails to build, report which one and why rather than silently skipping it.
-
-## Deliverables
-
- Refactored `flake.nix` using the composed module + generated-matrix approach.
- New `modules/build-types/*.nix` and `modules/platforms/*.nix` files.
- Old flat target names removed only after their replacements are verified.
- A short `README.md` (or section in existing docs) listing the final target
-  names and what each one is for.
- A summary at the end of what changed, what was removed, and any of the Open
-  Questions above that got resolved differently than expected.
-
-## Out of scope
-
- Don't touch `~/nix-auto-installer` contents beyond checking it for references
-  to the old target names — if changes there are needed, flag them, don't make
-  them without confirming.
- Don't add new build types or platforms beyond the ones listed here.
@@ -23,6 +23,8 @@
    let
      system = "x86_64-linux";
      inherit (nixpkgs) lib;
+      pkgs = nixpkgs.legacyPackages.${system};
+      vars = import ./variables.nix;

      # Generates a nixosConfiguration from a platform (what it runs on) and
      # a build type (what it's for), plus the per-identity host.nix that
@@ -31,6 +33,9 @@
      # nix-cache itself consumes the nix-cache substituter and remote
      # builder.
      mkTarget = { platform, buildType, hostPath, homeFile ? ./modules/common/home.nix }:
+        let
+          flakeTarget = "${platform}-${buildType}";
+        in
        nixpkgs.lib.nixosSystem {
          inherit system;
          modules = [
@@ -40,29 +45,36 @@
            ./modules/platforms/${platform}.nix
            ./modules/build-types/${buildType}.nix
            hostPath
-            { environment.etc."flake-target".text = "${platform}-${buildType}"; }
+            { environment.etc."flake-target".text = flakeTarget; }
            home-manager.nixosModules.home-manager
            {
              home-manager = {
                useGlobalPkgs = true;
                useUserPackages = true;
+                extraSpecialArgs = { inherit vars; };
                users.nixos = import homeFile;
              };
            }
          ] ++ lib.optionals (buildType != "nix-cache") [
            ./modules/nix-cache/client.nix
-            ./modules/remote-builder-client.nix
+            ./modules/nix-cache/remote-builder-client.nix
          ];
-          specialArgs = { inherit inputs; };
+          # flakeTarget is passed via specialArgs (not read back from
+          # config.environment.etc."flake-target" above) specifically so
+          # modules/platforms/lxc.nix can use it to select its own host key
+          # file without a same-option circular dependency (a module
+          # contributing to environment.etc can't read the merged
+          # environment.etc it's itself contributing to).
+          specialArgs = { inherit inputs vars netbootSystem netbootMinimalSystem flakeTarget; };
        };

      # Generated platform x build-type matrix. pxe-boot has no linode
      # variant (PXE/DHCP/TFTP need LAN L2 adjacency, which a Linode VPS
      # doesn't have).
      generatedTargets = {
-        linode-minimal = mkTarget { platform = "linode"; buildType = "minimal"; hostPath = ./hosts/linode-minimal/host.nix; };
-        proxmox-minimal = mkTarget { platform = "proxmox"; buildType = "minimal"; hostPath = ./hosts/proxmox-minimal/host.nix; };
-        lxc-minimal = mkTarget { platform = "lxc"; buildType = "minimal"; hostPath = ./hosts/lxc-minimal/host.nix; };
+        linode-minimal = mkTarget { platform = "linode"; buildType = "minimal"; hostPath = ./hosts/nix-minimal/host.nix; };
+        proxmox-minimal = mkTarget { platform = "proxmox"; buildType = "minimal"; hostPath = ./hosts/nix-minimal/host.nix; };
+        lxc-minimal = mkTarget { platform = "lxc"; buildType = "minimal"; hostPath = ./hosts/nix-minimal/host.nix; };

        linode-nix-cache = mkTarget { platform = "linode"; buildType = "nix-cache"; hostPath = ./hosts/nix-cache/host.nix; };
        proxmox-nix-cache = mkTarget { platform = "proxmox"; buildType = "nix-cache"; hostPath = ./hosts/nix-cache/host.nix; };
@@ -82,11 +94,116 @@

        proxmox-pxe-boot = mkTarget { platform = "proxmox"; buildType = "pxe-boot"; hostPath = ./hosts/pxe-boot/host.nix; };
        lxc-pxe-boot = mkTarget { platform = "lxc"; buildType = "pxe-boot"; hostPath = ./hosts/pxe-boot/host.nix; };
+
+        linode-tailscale-exit-node = mkTarget { platform = "linode"; buildType = "tailscale-exit-node"; hostPath = ./hosts/tailscale-exit-node/host.nix; };
+        proxmox-tailscale-exit-node = mkTarget { platform = "proxmox"; buildType = "tailscale-exit-node"; hostPath = ./hosts/tailscale-exit-node/host.nix; };
+        lxc-tailscale-exit-node = mkTarget { platform = "lxc"; buildType = "tailscale-exit-node"; hostPath = ./hosts/tailscale-exit-node/host.nix; };
+
+        lxc-tor-relay = mkTarget { platform = "lxc"; buildType = "tor-relay"; hostPath = ./hosts/tor-relay/host.nix; };
+      };
+
+      # Auto-install environments (migrated from the former nix-auto-installer
+      # flake): a self-contained NixOS installer that boots, discovers this
+      # flake's own nixosConfigurations over the network, and runs
+      # nixos-install against whichever one the operator picks. These are
+      # deliberately not part of the platform x build-type matrix above —
+      # they're throwaway boot media, not persistent hosts, so they skip
+      # disko/sops-nix/home-manager and just need `vars`.
+      installerTargets = {
+        installer = nixpkgs.lib.nixosSystem {
+          inherit system;
+          modules = [ ./modules/installer/iso.nix ];
+          specialArgs = { inherit vars; };
+        };
+      };
+
+      # Same installer environment, built as netboot (kernel + initrd +
+      # iPXE script) instead of an ISO — this is what packages.pxe bundles.
+      #
+      # Deliberately imports common.nix directly, NOT ./modules/installer/iso.nix
+      # (which pulls in nixpkgs' installation-cd-minimal.nix) -- confirmed live
+      # that composing the ISO module together with netboot-minimal.nix hangs
+      # every boot waiting for a device that can never exist on a netboot
+      # client ("A start job is running for /dev/disk/by-label/nixos-minimal-...").
+      # Both installation-cd-base.nix and netboot.nix set fileSystems."/" via
+      # the identical lib.mkImageMediaOverride (mkOverride 60) priority --
+      # genuinely conflicting root-filesystem strategies (ISO-by-label vs.
+      # netboot-tmpfs) at the same priority, and the ISO one was winning.
+      # netboot-minimal.nix's own chain (netboot-base.nix) already imports
+      # profiles/installation-device.nix independently, so common.nix's
+      # initialHashedPassword override (which assumes that profile is
+      # present) still applies correctly without iso.nix in the mix.
+      #
+      # networking.hostName is set explicitly (rather than left at nixpkgs'
+      # own "nixos" default) so this image's generated system name
+      # (nixos-system-auto-installer-*) matches its iPXE menu entry —
+      # see modules/build-types/pxe-boot.nix's :auto-installer item — and
+      # its staged directory, /srv/pxe/http/auto-installer.
+      netbootSystem = nixpkgs.lib.nixosSystem {
+        inherit system;
+        modules = [
+          ./modules/installer/common.nix
+          ({ modulesPath, ... }: {
+            imports = [
+              (modulesPath + "/installer/netboot/netboot-minimal.nix")
+            ];
+          })
+          { networking.hostName = "auto-installer"; }
+        ];
+        specialArgs = { inherit vars; };
+      };
+
+      # A genuinely vanilla NixOS minimal netboot image: nixpkgs'
+      # netboot-minimal.nix on its own, with none of this flake's
+      # auto-installer wiring (no common.nix — no auto-install.sh, no
+      # baked host keys, no custom users/passwords). Built from source via
+      # the same nixosSystem + netboot-minimal.nix path as netbootSystem
+      # above, so both go through an identical build mechanism; the only
+      # difference is what's composed in. hostName again matches this
+      # image's iPXE menu entry (:nixos-minimal) and staged directory
+      # (/srv/pxe/http/nixos-minimal).
+      netbootMinimalSystem = nixpkgs.lib.nixosSystem {
+        inherit system;
+        modules = [
+          ({ modulesPath, ... }: {
+            imports = [
+              (modulesPath + "/installer/netboot/netboot-minimal.nix")
+            ];
+          })
+          { networking.hostName = "nixos-minimal"; }
+        ];
      };

    in
    {

-      nixosConfigurations = generatedTargets;
+      nixosConfigurations = generatedTargets // installerTargets;
+
+      # Buildable auto-installer artifacts (`nix build .#<name>`). No `lxc`
+      # variant (installer-boots-as-an-LXC-container) or `all` bundle
+      # anymore — lxc-* and proxmox-* hosts deploy via their own tarball/
+      # disk-image outputs instead (see docs/auto-installer.md and
+      # docs/proxmox-images.md), which left the installer's own LXC form
+      # with no real use case: it's excluded from the install menu (same
+      # bind-mount problem as any LXC nixos-install target) and nothing
+      # else needed booting the installer itself as a container.
+      packages.${system} = {
+        iso = installerTargets.installer.config.system.build.isoImage;
+
+        pxe = pkgs.linkFarm "pxe" [
+          { name = "netboot.ipxe"; path = netbootSystem.config.system.build.netbootIpxeScript; }
+          { name = "initrd"; path = netbootSystem.config.system.build.netbootRamdisk; }
+          { name = "kernel"; path = netbootSystem.config.system.build.kernel; }
+        ];
+
+        # Vanilla NixOS minimal netboot bundle — see netbootMinimalSystem
+        # above. Staged onto the pxe-boot host alongside packages.pxe by
+        # modules/pxe-boot/stage-installer-artifacts.nix.
+        pxe-minimal = pkgs.linkFarm "pxe-minimal" [
+          { name = "netboot.ipxe"; path = netbootMinimalSystem.config.system.build.netbootIpxeScript; }
+          { name = "initrd"; path = netbootMinimalSystem.config.system.build.netbootRamdisk; }
+          { name = "kernel"; path = netbootMinimalSystem.config.system.build.kernel; }
+        ];
+      };
    };
 }
@@ -1,4 +1,4 @@
-{ ... }:
+_:

 {
  networking.hostName = "docker";
@@ -1,9 +0,0 @@
-{ ... }:
-
-{
-  networking.hostName = "linode-minimal";
-
-  # Preserved from the pre-refactor `linode-minimal` target — stateVersion
-  # must never be bumped on an already-installed machine.
-  system.stateVersion = "26.05";
-}
@@ -1,9 +0,0 @@
-{ ... }:
-
-{
-  networking.hostName = "lxc-minimal";
-
-  # No pre-existing deployed machine to preserve — pin explicitly to the
-  # current release rather than let it silently default.
-  system.stateVersion = "26.05";
-}
@@ -1,19 +1,19 @@
-{ config, ... }:
+{ vars, ... }:

 {
-  networking.hostName = "nix-cache";
+  imports = [
+    (import ../../modules/beszel/host-token.nix {
+      name = "nix-cache";
+      sopsFile = ../../secrets/nix-cache.yaml;
+    })
+  ];

-  sops.secrets."beszel-token".sopsFile = ../../secrets/nix-cache.yaml;
-  sops.templates."nix-cache-beszel.env".content = ''
-    TOKEN=${config.sops.placeholder."beszel-token"}
-  '';
+  networking.hostName = vars.nixCacheHost;

  services.beszel.agent.environment = {
    #DOCKER_HOST = "tcp://docker-socket-proxy:2375";
-    #HUB_URL = "http://docker.sweet.home:8090";
    KEY = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFPR9kwtC4TAeTRu46A7+opZsYpxqkRJ+x/ZyB2GWCeG";
  };
-  services.beszel.agent.environmentFile = config.sops.templates."nix-cache-beszel.env".path;

  # Preserved from the pre-refactor `nix-cache` target — stateVersion must
  # never be bumped on an already-installed machine.
@@ -1,4 +1,4 @@
-{ ... }:
+_:

 {
  # Preserves the hostname of the existing, already-deployed machine
@@ -1,79 +1,82 @@
-{ config, pkgs, lib, ... }:
+{ config, pkgs, lib, vars, ... }:

 {

-    imports = [
+  imports = [
    ../../modules/common/aliases.nix
  ];

-  home.username = "nixos";         # your actual username
-  home.homeDirectory = "/home/nixos";
-  home.stateVersion = "25.05";        # match your NixOS stateVersion
+  home = {
+    username = vars.primaryUser;
+    homeDirectory = "/home/${vars.primaryUser}";
+    stateVersion = "25.05"; # match your NixOS stateVersion

-  programs.home-manager.enable = true;  # mandatory to activate HM
+    # Optional: packages
+    packages = with pkgs; [
+      git
+      vim
+      tmux
+      nextcloud-client
+      #    vscode
+      chromium
+    ];

-  # Optional: packages
-  home.packages = with pkgs; [
-    git
-    vim
-    tmux
-    nextcloud-client
-#    vscode
-    chromium
-  ];
+    # Optional: set environment vars
+    sessionVariables = {
+      EDITOR = "vim";
+    };

-  # Optional: set environment vars
-  home.sessionVariables = {
-    EDITOR = "vim";
+    file = {
+      ".local/share/applications/proxmox-chromium-app.desktop".text = ''
+        [Desktop Entry]
+        Type=Application
+        Name=Proxmox (Chromium)
+        Exec=chromium --app=https://pve.${vars.homeDomain}:${toString vars.ports.pveWeb} --window-size=1920,1080 --window-position=0,0
+        Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
+        Terminal=false
+        Categories=Hypervisor;
+        StartupWMClass=PVE
+      '';
+      ".local/share/applications/pbs-chromium-app.desktop".text = ''
+        [Desktop Entry]
+        Type=Application
+        Name=Proxmox Backup Server (Chromium)
+        Exec=chromium --app=https://${vars.pbsIp}:${toString vars.ports.pbsWeb} --window-size=1920,1080 --window-position=0,0
+        Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
+        Terminal=false
+        Categories=backup;
+
+      '';
+      ".local/share/applications/proxmox-firefox-app.desktop".text = ''
+        [Desktop Entry]
+        Type=Application
+        Name=Proxmox (Firefox)
+        Exec=firefox --new-instance https://pve.${vars.homeDomain}:${toString vars.ports.pveWeb} --profile ProxmoxWebApp --window-size=1920,1080 --class ProxmoxWebApp
+        Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
+        Terminal=false
+        Categories=Hypervisor;
+        StartupWMClass=PVE
+      '';
+      ".local/share/applications/pbs-firefox-app.desktop".text = ''
+        [Desktop Entry]
+        Type=Application
+        Name=Proxmox Backup Server (Firefox)
+        Exec=firefox --new-window https://${vars.pbsIp}:${toString vars.ports.pbsWeb} --profile PbsWebApp --window-size=1920,1080 --class PbsWebApp
+        Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
+        Terminal=false
+        Categories=backup;
+        StartupWMClass=PBS
+      '';
+    };
  };

+  programs.home-manager.enable = true; # mandatory to activate HM
+
  # Optional: enable bash (or zsh, fish...)
  programs.bash.enable = true;
-    services.nextcloud-client = {
+  services.nextcloud-client = {
    enable = true;
    # Optionally start in background directly
    startInBackground = true;
  };
-home.file = {
-  ".local/share/applications/proxmox-chromium-app.desktop".text = ''
-    [Desktop Entry]
-    Type=Application
-    Name=Proxmox (Chromium)
-    Exec=chromium --app=https://pve.sweet.home:8006 --window-size=1920,1080 --window-position=0,0
-    Icon=/home/nixos/.local/share/icons/proxmox.png
-    Terminal=false
-    Categories=Hypervisor;
-    StartupWMClass=PVE
-  '';
-  ".local/share/applications/pbs-chromium-app.desktop".text = ''
-    [Desktop Entry]
-    Type=Application
-    Name=Proxmox Backup Server (Chromium)
-    Exec=chromium --app=https://192.168.2.108:8007 --window-size=1920,1080 --window-position=0,0
-    Icon=/home/nixos/.local/share/icons/proxmox.png
-    Terminal=false
-    Categories=backup;
-
-  '';
-  ".local/share/applications/proxmox-firefox-app.desktop".text = ''
-    [Desktop Entry]
-    Type=Application
-    Name=Proxmox (Firefox)
-    Exec=firefox --new-instance https://pve.sweet.home:8006 --profile ProxmoxWebApp --window-size=1920,1080 --class ProxmoxWebApp
-    Icon=/home/nixos/.local/share/icons/proxmox.png
-    Terminal=false
-    Categories=Hypervisor;
-    StartupWMClass=PVE
-  '';
-  ".local/share/applications/pbs-firefox-app.desktop".text = ''
-    [Desktop Entry]
-    Type=Application
-    Name=Proxmox Backup Server (Firefox)
-    Exec=firefox --new-window https://192.168.2.108:8007 --profile PbsWebApp --window-size=1920,1080 --class PbsWebApp
-    Icon=/home/nixos/.local/share/icons/proxmox.png
-    Terminal=false
-    Categories=backup;
-    StartupWMClass=PBS
-  '';
-};
-}
+}
@@ -1,4 +1,4 @@
-{ ... }:
+_:

 {
  networking.hostName = "nixos";
@@ -1,4 +1,4 @@
-{ ... }:
+_:

 {
  networking.hostName = "pxe-boot";
@@ -1,22 +1,22 @@
-{ config, ... }:
+{ vars, ... }:

 {
-  networking.hostName = "server";
-  networking.hostId = "6689f93e";
+  imports = [
+    (import ../../modules/beszel/host-token.nix {
+      name = "server";
+      sopsFile = ../../secrets/server.yaml;
+    })
+  ];

-  sops.secrets."beszel-token".sopsFile = ../../secrets/server.yaml;
-  sops.templates."server-beszel.env".content = ''
-    TOKEN=${config.sops.placeholder."beszel-token"}
-  '';
+  networking.hostName = vars.nfsServerHost;
+  networking.hostId = "6689f93e";

  services.beszel.agent.environment = {
    #DOCKER_HOST = "tcp://docker-socket-proxy:2375";
-    #HUB_URL = "http://docker.sweet.home:8090";
    KEY = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFPR9kwtC4TAeTRu46A7+opZsYpxqkRJ+x/ZyB2GWCeG";
-    EXTRA_FILESYSTEMS = "/tank/docker/volumes";
+    EXTRA_FILESYSTEMS = "${vars.storageRoot}/${vars.nfsShares.dockerVolumes.subpath}";
    LOG_LEVEL = "debug";
  };
-  services.beszel.agent.environmentFile = config.sops.templates."server-beszel.env".path;

  # Preserved from the pre-refactor `server` target — stateVersion must never
  # be bumped on an already-installed machine.
@@ -0,0 +1,12 @@
+_:
+
+{
+  networking.hostName = "exit-node";
+
+  # No networking.hostId: only ZFS-touching hosts (server, docker) need one
+  # for pool-import safety, and this host does neither.
+
+  # A genuinely new host (not a pre-refactor carry-over), so it tracks the
+  # flake's current nixpkgs release rather than being pinned to an older one.
+  system.stateVersion = "26.05";
+}
@@ -0,0 +1,12 @@
+_:
+
+{
+  networking.hostName = "tor-relay";
+
+  # No networking.hostId: only ZFS-touching hosts (server, docker) need one
+  # for pool-import safety, and this host does neither.
+
+  # A genuinely new host (not a pre-refactor carry-over), so it tracks the
+  # flake's current nixpkgs release rather than being pinned to an older one.
+  system.stateVersion = "26.05";
+}
@@ -1,9 +1,18 @@
-{ ... }:
+{ vars, ... }:

 {
-services.beszel.agent.enable = true;
-services.beszel.agent.environment = {
-#DOCKER_HOST = "tcp://docker-socket-proxy:2375";
-HUB_URL = "http://docker.sweet.home:8090";
-};
+  services.beszel.agent.enable = true;
+  services.beszel.agent.environment = {
+    #DOCKER_HOST = "tcp://docker-socket-proxy:2375";
+    HUB_URL = "http://${vars.dockerHost}.${vars.homeDomain}:${toString vars.ports.beszelHub}";
+  };
+
+  # The upstream module runs beszel-agent under DynamicUser with
+  # ProtectSystem = "strict" and no StateDirectory, so /var/lib/beszel-agent
+  # (where the agent persists its hub-pairing fingerprint, per
+  # https://github.com/henrygd/beszel/discussions/1542) isn't writable --
+  # every restart silently fails to save it and regenerates a fresh one in
+  # memory, permanently desyncing from whatever the hub has on record after
+  # the very first successful pairing. Give it real persistent storage.
+  systemd.services.beszel-agent.serviceConfig.StateDirectory = "beszel-agent";
 }
@@ -0,0 +1,11 @@
+{ name, sopsFile }:
+
+{ config, ... }:
+
+{
+  sops.secrets."beszel-token".sopsFile = sopsFile;
+  sops.templates."${name}-beszel.env".content = ''
+    TOKEN=${config.sops.placeholder."beszel-token"}
+  '';
+  services.beszel.agent.environmentFile = config.sops.templates."${name}-beszel.env".path;
+}
@@ -1,6 +1,6 @@
-{ ... }:
+_:

 {
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;
-}
+}
@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, vars, ... }:

 {
  # Pins the Docker Engine version, carried forward from the pre-refactor
@@ -13,11 +13,11 @@
  imports = [
    ../docker/mount-data.nix
    ../docker/enable-service.nix
+    ../docker/nextcloud-cron-job.nix
+    ../docker/docker-health-to-gotify.nix
    ../tailscale/enable-service.nix
-    ../rotate-traefik-logs.nix
+    ../traefik/rotate-logs.nix
    ../raspi/mount-data.nix
-    ../services/nextcloud-cron-job.nix
-    ../services/docker-health-to-gotify.nix
    ../services/enable-rpcbind.nix
  ];

@@ -28,13 +28,18 @@
  boot.supportedFilesystems = [ "nfs" ];

  systemd.tmpfiles.rules = [
-    "L+ /home/nixos/docker - - - - /mnt/docker/config"
-    "d /mnt/docker 0755 nixos users -"
-    "d /mnt/raspi-backup 0755 nixos users -"
+    "L+ /home/${vars.primaryUser}/docker - - - - ${vars.nfsShares.dockerConfig.mountpoint}"
+    "d /mnt/docker 0755 ${vars.primaryUser} users -"
+    "d ${vars.nfsShares.raspiVolumes.mountpoint} 0755 ${vars.primaryUser} users -"
  ];

-  users.users.nixos.extraGroups = [ "docker" ];
+  users.users.${vars.primaryUser}.extraGroups = [ "docker" ];
  services.openssh.settings.PermitRootLogin = "yes";

-  networking.firewall.allowedTCPPorts = [ 80 8080 443 8090 ];
+  networking.firewall.allowedTCPPorts = [
+    vars.ports.dockerHttp
+    vars.ports.dockerExtra
+    vars.ports.dockerHttps
+    vars.ports.beszelHub
+  ];
 }
@@ -1,8 +1,8 @@
-{ config, pkgs, lib, inputs, ... }:
+{ config, pkgs, lib, inputs, vars, ... }:

 {
  environment.systemPackages = with pkgs; [
-    inputs.nixos-conf-editor.packages.${pkgs.system}.nixos-conf-editor
+    inputs.nixos-conf-editor.packages.${pkgs.stdenv.hostPlatform.system}.nixos-conf-editor
    nodejs
    appimage-run
    seahorse
@@ -19,39 +19,55 @@

  boot.loader.grub.useOSProber = true;

-  services.xserver.enable = true;
-  services.xserver.displayManager.lightdm.enable = true;
-  services.xserver.desktopManager.cinnamon.enable = true;
+  services = {
+    xserver = {
+      enable = true;

-  services.xserver.xkb = {
-    layout = "au";
-    variant = "";
+      displayManager = {
+        lightdm.enable = true;
+        sessionCommands = ''
+          eval $(gnome-keyring-daemon --start --components=secrets,ssh)
+          export SSH_AUTH_SOCK
+        '';
+      };
+
+      desktopManager.cinnamon.enable = true;
+
+      xkb = {
+        layout = "au";
+        variant = "";
+      };
+    };
+
+    printing.enable = true;
+
+    pipewire = {
+      enable = true;
+      alsa.enable = true;
+      alsa.support32Bit = true;
+      pulse.enable = true;
+    };
+
+    xrdp = {
+      enable = true;
+      defaultWindowManager = "cinnamon-session";
+      openFirewall = true;
+    };
+
+    gnome.gnome-keyring.enable = true;
  };

-  services.printing.enable = true;
-
-  security.rtkit.enable = true;
-  services.pipewire = {
-    enable = true;
-    alsa.enable = true;
-    alsa.support32Bit = true;
-    pulse.enable = true;
+  security = {
+    rtkit.enable = true;
+    pam.services.login.enableGnomeKeyring = true;
  };

-  users.users.nixos.extraGroups = [ "networkmanager" ];
+  # The networkmanager group only exists when NM is actually enabled — the
+  # lxc platform module force-disables it, so don't add the user to a group
+  # that won't exist there.
+  users.users.${vars.primaryUser}.extraGroups = lib.mkIf config.networking.networkmanager.enable [ "networkmanager" ];

  programs.firefox.enable = true;

-  services.xrdp.enable = true;
-  services.xrdp.defaultWindowManager = "cinnamon-session";
-  services.xrdp.openFirewall = true;
  nixpkgs.config.allowUnfree = true;
-
-  services.gnome.gnome-keyring.enable = true;
-  security.pam.services.login.enableGnomeKeyring = true;
-
-  services.xserver.displayManager.sessionCommands = ''
-    eval $(gnome-keyring-daemon --start --components=secrets,ssh)
-    export SSH_AUTH_SOCK
-  '';
 }
@@ -1,9 +1,12 @@
-{ pkgs, ... }:
+{ lib, pkgs, config, vars, ... }:

 {
  networking.networkmanager.enable = true;

-  users.users.nixos.extraGroups = [ "networkmanager" ];
+  # The networkmanager group only exists when NM is actually enabled — the
+  # lxc platform module force-disables it, so don't add the user to a group
+  # that won't exist there.
+  users.users.${vars.primaryUser}.extraGroups = lib.mkIf config.networking.networkmanager.enable [ "networkmanager" ];

  environment.systemPackages = with pkgs; [
    inetutils
@@ -1,10 +1,10 @@
-{ config, lib, pkgs, inputs, ... }:
+{ config, lib, pkgs, inputs, vars, ... }:

 let
  pxeRoot = "/srv/pxe";
  httpRoot = "${pxeRoot}/http";
  tftpRoot = "${pxeRoot}/tftp";
-  pxeBaseUrl = "http://192.168.2.247";
+  pxeBaseUrl = "http://${vars.pxeServerIp}";

  bootIpxe = pkgs.writeText "boot.ipxe" ''
    #!ipxe
@@ -68,17 +68,19 @@ let
    set base ${pxeBaseUrl}

    menu PXE Boot Menu
-    item nixos NixOS Installer
+    item auto-installer NixOS Auto-Installer
+    item nixos-minimal NixOS Minimal
    item rescue Rescue Environment
    item shell iPXE Shell
    item reboot Reboot

    choose target && goto ''${target}

-    :nixos
-    kernel ''${base}/nixos/bzImage ip=dhcp
-    initrd ''${base}/nixos/initrd
-    boot
+    :auto-installer
+    chain ''${base}/auto-installer/netboot.ipxe
+
+    :nixos-minimal
+    chain ''${base}/nixos-minimal/netboot.ipxe

    :rescue
    chain ''${base}/systemrescue.ipxe
@@ -91,39 +93,48 @@ let
  '';
 in
 {
+  imports = [
+    ../pxe-boot/stage-installer-artifacts.nix
+  ];
+
  environment.systemPackages = with pkgs; [
    ipxe
  ];

-  services.nginx = {
-    enable = true;
+  services = {
+    nginx = {
+      enable = true;

-    virtualHosts."pxe-boot" = {
-      default = true;
-      root = httpRoot;
-      locations."/" = {
-        extraConfig = ''
-          autoindex on;
-        '';
+      virtualHosts."pxe-boot" = {
+        default = true;
+        root = httpRoot;
+        locations."/" = {
+          extraConfig = ''
+            autoindex on;
+          '';
+        };
      };
    };
-  };

-  # TFTP is only used to deliver the initial iPXE bootloader. After iPXE
-  # starts, all further assets are fetched via nginx over HTTP.
-  services.atftpd = {
-    enable = true;
-    root = tftpRoot;
-    extraOptions = [
-      "--verbose=5"
-    ];
+    # TFTP is only used to deliver the initial iPXE bootloader. After iPXE
+    # starts, all further assets are fetched via nginx over HTTP.
+    atftpd = {
+      enable = true;
+      root = tftpRoot;
+      extraOptions = [
+        "--verbose=5"
+      ];
+    };
+
+    openssh.settings.PermitRootLogin = "yes";
  };

  systemd.tmpfiles.rules = [
    "d ${pxeRoot} 0755 root root -"
    "d ${httpRoot} 0755 root root -"
    "d ${httpRoot}/images 0755 root root -"
-    "d ${httpRoot}/nixos 0755 root root -"
+    "d ${httpRoot}/auto-installer 0755 root root -"
+    "d ${httpRoot}/nixos-minimal 0755 root root -"
    "d ${httpRoot}/systemrescue 0755 root root -"
    "d ${httpRoot}/ubuntu 0755 root root -"
    "d ${httpRoot}/rescue 0755 root root -"
@@ -149,8 +160,6 @@ in
    };
  };

-  services.openssh.settings.PermitRootLogin = "yes";
-
-  networking.firewall.allowedTCPPorts = [ 80 ];
-  networking.firewall.allowedUDPPorts = [ 69 ];
+  networking.firewall.allowedTCPPorts = [ vars.ports.pxeBootHttp ];
+  networking.firewall.allowedUDPPorts = [ vars.ports.pxeBootTftp ];
 }
@@ -1,4 +1,4 @@
-{ ... }:
+{ vars, lib, ... }:

 {
  imports = [
@@ -6,7 +6,7 @@
    ../services/zfs/enable-service.nix
  ];

-  boot.zfs.extraPools = [ "tank" ];
+  boot.zfs.extraPools = [ (lib.removePrefix "/" vars.storageRoot) ];

  systemd.services.nfs-server = {
    after = [ "zfs-mount.service" ];
@@ -16,13 +16,13 @@
  services.nfs.server = {
    enable = true;
    exports = ''
-      /tank/docker/config 192.168.2.0/24(rw,sync,no_subtree_check,no_root_squash)
-      /tank/docker/volumes 192.168.2.0/24(rw,sync,no_subtree_check,no_root_squash)
-      /tank/docker/databases 192.168.2.0/24(rw,sync,no_subtree_check,no_root_squash)
-      /tank/docker/nextcloud-data 192.168.2.0/24(rw,sync,no_subtree_check,no_root_squash)
-      /tank/raspi/volumes 192.168.2.0/24(rw,sync,no_subtree_check,no_root_squash)
+      ${vars.storageRoot}/${vars.nfsShares.dockerConfig.subpath} ${vars.lanCidr}(rw,sync,no_subtree_check,no_root_squash)
+      ${vars.storageRoot}/${vars.nfsShares.dockerVolumes.subpath} ${vars.lanCidr}(rw,sync,no_subtree_check,no_root_squash)
+      ${vars.storageRoot}/${vars.nfsShares.dockerDatabases.subpath} ${vars.lanCidr}(rw,sync,no_subtree_check,no_root_squash)
+      ${vars.storageRoot}/${vars.nfsShares.nextcloudData.subpath} ${vars.lanCidr}(rw,sync,no_subtree_check,no_root_squash)
+      ${vars.storageRoot}/${vars.nfsShares.raspiVolumes.subpath} ${vars.lanCidr}(rw,sync,no_subtree_check,no_root_squash)
    '';
  };

-  networking.firewall.allowedTCPPorts = [ 111 2049 ];
+  networking.firewall.allowedTCPPorts = [ vars.ports.nfsRpcbind vars.ports.nfsd ];
 }
@@ -0,0 +1,21 @@
+{ ... }:
+
+{
+  imports = [
+    ../tailscale/exit-node.nix
+  ];
+
+  # "server", not "both": this build type only ever advertises itself as an
+  # exit node (see ../tailscale/exit-node.nix) -- it doesn't advertise LAN
+  # subnet routes, so it doesn't need the "client"-side loose reverse-path
+  # filtering that "both" would also turn on. Deliberately left unbundled
+  # from LAN-subnet-route advertisement so this build type stays valid on
+  # every platform, including linode (a remote VPS with no network path to
+  # the home LAN at all).
+  services.tailscale.useRoutingFeatures = "server";
+
+  # Forwarded exit-node traffic arrives on tailscale0 already
+  # tailscale-authenticated -- the firewall's normal per-port allow-list
+  # would otherwise drop it. Standard NixOS/Tailscale exit-node guidance.
+  networking.firewall.trustedInterfaces = [ "tailscale0" ];
+}
@@ -0,0 +1,7 @@
+{ ... }:
+
+{
+  imports = [
+    ../tor/enable-relay.nix
+  ];
+}
@@ -1,4 +1,4 @@
-{ config, pkgs, lib, ... }:
+{ config, pkgs, lib, vars, ... }:

 let
  # Flake attribute names are now <platform>-<buildtype> (e.g. proxmox-docker)
@@ -9,13 +9,33 @@ let
    sudo nixos-rebuild switch \
      --no-write-lock-file \
      --refresh \
-      --flake git+https://gitea.lan.ddnsgeek.com/beatzaplenty/nixos.git#$(cat /etc/flake-target)
+      --flake git+https://${vars.lanDomain}/beatzaplenty/nixos.git#$(cat /etc/flake-target)
  '';
  myTestCmd = ''
    sudo nixos-rebuild test \
      --no-write-lock-file \
      --refresh \
-      --flake git+https://gitea.lan.ddnsgeek.com/beatzaplenty/nixos.git#$(cat /etc/flake-target)
+      --flake git+https://${vars.lanDomain}/beatzaplenty/nixos.git#$(cat /etc/flake-target)
+  '';
+
+  # lxc-* hosts pre-seed their SSH host key at build time (see
+  # modules/platforms/lxc.nix) so sops-nix's .sops.yaml recipient matches on
+  # first boot -- without it, secrets permanently fail to decrypt (see that
+  # file's comment for the confirmed failure). That requires --impure plus
+  # NIXOS_HOST_KEYS_DIR pointing at the repo's host-keys/ dir, same pattern
+  # docs/auto-installer.md uses for the installer ISO. A function, not a
+  # shellAlias, since the target name has to interpolate into the middle of
+  # the flake attribute path, not just append after it. Must be run from the
+  # repo root, same as every other host-keys/ command in this repo.
+  buildImageFn = ''
+    buildImage() {
+      if [ -z "$1" ]; then
+        echo "usage: buildImage <flake-target>  (e.g. lxc-docker)" >&2
+        return 1
+      fi
+      NIXOS_HOST_KEYS_DIR="$(pwd)/host-keys" nix build --impure \
+        ".#nixosConfigurations.$1.config.system.build.tarball"
+    }
  '';
 in
 {
@@ -25,5 +45,6 @@ in
      "Switch-nix" = mySwitchCmd;
      "Test-nix" = myTestCmd;
    };
+    initExtra = buildImageFn;
  };
 }
@@ -1,29 +1,36 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, vars, ... }:

 {
-    imports =
-    [ # Include the results of the hardware scan.
-#      ./hardware-configuration.nix
-      ../set-locale.nix
+  imports =
+    [
+      # Include the results of the hardware scan.
+      #      ./hardware-configuration.nix
+      ./set-locale.nix
    ];
  # Use the GRUB 2 boot loader.
  # boot.loader.grub.enable = true;
  #boot.loader.grub.device = "/dev/sda"; # or "nodev" for efi only

-  networking.networkmanager.enable = true;  # Easiest to use and most distros use this by default.
+  networking.networkmanager.enable = true; # Easiest to use and most distros use this by default.
+
+  # Recommended over the true default (bypasses ZFS's own import safeguards)
+  # per the option's own docs; matches hosts/docker/host.nix and
+  # modules/services/zfs/enable-service.nix, which already set this
+  # explicitly. Harmless no-op on hosts that don't use ZFS at all.
+  boot.zfs.forceImportRoot = false;

  # Set your time zone.
-  time.timeZone = "Australia/Brisbane";
+  time.timeZone = vars.timeZone;

  # Enable QEMU agent
  services.qemuGuest.enable = true;

-    # Enable docker-compose
+  # Enable docker-compose
  environment.systemPackages = with pkgs; [
-  vim
-  btop
-  git
-  gcr
+    vim
+    btop
+    git
+    gcr
  ];

  # Secrets shared by every host, decrypted at activation via each host's
@@ -32,28 +39,34 @@
  # or docs/ for the sops workflow). hashedPassword/hashedPasswordFile need
  # neededForUsers so they're available before the normal secret-activation
  # step, since user creation happens very early in boot.
-  sops.defaultSopsFile = ../../secrets/common.yaml;
-  sops.secrets."root-hashedPassword".neededForUsers = true;
-  sops.secrets."nixos-hashedPassword".neededForUsers = true;
-  sops.secrets."nix-github-token" = { };
+  sops = {
+    defaultSopsFile = ../../secrets/common.yaml;
+
+    secrets = {
+      "root-hashedPassword".neededForUsers = true;
+      "nixos-hashedPassword".neededForUsers = true;
+      "nix-github-token" = { };
+    };
+
+    # nix.conf doesn't support a *File-style option for access-tokens, so the
+    # token is rendered into a runtime-only file (never touches the Nix store)
+    # and pulled in via nix.conf's native !include directive.
+    templates."nix-github-token.conf".content = ''
+      access-tokens = github.com=${config.sops.placeholder."nix-github-token"}
+    '';
+  };

-  # nix.conf doesn't support a *File-style option for access-tokens, so the
-  # token is rendered into a runtime-only file (never touches the Nix store)
-  # and pulled in via nix.conf's native !include directive.
-  sops.templates."nix-github-token.conf".content = ''
-    access-tokens = github.com=${config.sops.placeholder."nix-github-token"}
-  '';
  nix.extraOptions = ''
    !include ${config.sops.templates."nix-github-token.conf".path}
  '';

-#Set root password
-users.users.root = {
-  hashedPasswordFile = config.sops.secrets."root-hashedPassword".path;
-};
+  #Set root password
+  users.users.root = {
+    hashedPasswordFile = config.sops.secrets."root-hashedPassword".path;
+  };

  # Define a user account. Don't forget to set a password with ‘passwd’.
-  users.users.nixos = {
+  users.users.${vars.primaryUser} = {
    isNormalUser = true;
    extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
    packages = with pkgs; [
@@ -61,8 +74,8 @@ users.users.root = {
    ];
    hashedPasswordFile = config.sops.secrets."nixos-hashedPassword".path;
    openssh.authorizedKeys.keys = [
-    "ssh-rsa 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 wayne@stream"
-    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICMJhrfFayLBG+gWtO6oAvgambw5nWWgztiTFEaaaVRH debian@surface"
+      vars.adminSshKey
+      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICMJhrfFayLBG+gWtO6oAvgambw5nWWgztiTFEaaaVRH debian@surface"
    ];
  };

@@ -88,4 +101,4 @@ users.users.root = {



-}
+}
@@ -1,65 +1,69 @@
-{ config, pkgs, lib, ... }:
+{ config, pkgs, lib, vars, ... }:

 let
  remote = "root@proxmox-ip:/var/lib/vz/template/iso";
  localMount = "${config.home.homeDirectory}/proxmox-iso";
-in {
+in
+{

  imports = [
    ./aliases.nix
  ];

-  home.username = "nixos";         # your actual username
-  home.homeDirectory = "/home/nixos";
-  home.stateVersion = "25.11";        # match your NixOS stateVersion
+  home = {
+    username = vars.primaryUser;
+    homeDirectory = "/home/${vars.primaryUser}";
+    stateVersion = "25.11"; # match your NixOS stateVersion
+
+    # Optional: packages
+    packages = with pkgs; [
+      git
+      vim
+      tmux
+      nano
+      sshfs
+    ];
+
+    # Optional: set environment vars
+    sessionVariables = {
+      EDITOR = "nano";
+    };
+  };
+
+  programs.home-manager.enable = true; # mandatory to activate HM
+
+  programs.bash.enable = true;

-  programs.home-manager.enable = true;  # mandatory to activate HM
-  
-programs.bash.enable = true;
-  
  # GitHub access-tokens setting used to live here in plaintext; it's now
  # rendered system-wide from a sops-nix secret via nix.extraOptions in
  # modules/common/configuration.nix instead (covers the daemon for every
  # user, not just this one).

-  # Optional: packages
-  home.packages = with pkgs; [
-    git
-    vim
-    tmux
-    nano
-    sshfs
-  ];
+  #  systemd.user.services.mount-proxmox-iso = {
+  #    Unit = {
+  #      Description = "Mount Proxmox ISO dir via SSHFS";
+  #      After = [ "network-online.target" ];
+  #      Wants = [ "network-online.target" ];
+  #    };

-  # Optional: set environment vars
-  home.sessionVariables = {
-    EDITOR = "nano";
-  };
-#  systemd.user.services.mount-proxmox-iso = {
-#    Unit = {
-#      Description = "Mount Proxmox ISO dir via SSHFS";
-#      After = [ "network-online.target" ];
-#      Wants = [ "network-online.target" ];
-#    };
+  #    Service = {
+  #      Type = "simple";
+  #      ExecStartPre = "${pkgs.coreutils}/bin/mkdir -p ${localMount}";
+  #      ExecStart = "${pkgs.sshfs}/bin/sshfs -o IdentityFile=${config.home.homeDirectory}/.ssh/id_ed25519,allow_other,reconnect,ServerAliveInterval=15,ServerAliveCountMax=3 root@proxmox-ip:/var/lib/vz/template/iso ${localMount}";
+  #      ExecStop = "${pkgs.fuse3}/bin/fusermount3 -u ${localMount}";
+  #      Restart = "on-failure";
+  #    };

-#    Service = {
-#      Type = "simple";
-#      ExecStartPre = "${pkgs.coreutils}/bin/mkdir -p ${localMount}";
-#      ExecStart = "${pkgs.sshfs}/bin/sshfs -o IdentityFile=${config.home.homeDirectory}/.ssh/id_ed25519,allow_other,reconnect,ServerAliveInterval=15,ServerAliveCountMax=3 root@proxmox-ip:/var/lib/vz/template/iso ${localMount}";
-#      ExecStop = "${pkgs.fuse3}/bin/fusermount3 -u ${localMount}";
-#      Restart = "on-failure";
-#    };
-
-#    Install = {
-#      WantedBy = [ "default.target" ];
-#    };
-#  };
+  #    Install = {
+  #      WantedBy = [ "default.target" ];
+  #    };
+  #  };
  # Optional: enable bash (or zsh, fish...)
-#  programs.bash.enable = true;
+  #  programs.bash.enable = true;

  # Optional: manage dotfiles via symlinks
-#  home.file = {
-#    ".tmux.conf".source = ./dotfiles/tmux.conf;
-#    ".config/nvim/init.vim".source = ./dotfiles/init.vim;
-#  };
+  #  home.file = {
+  #    ".tmux.conf".source = ./dotfiles/tmux.conf;
+  #    ".config/nvim/init.vim".source = ./dotfiles/init.vim;
+  #  };
 }
@@ -1,4 +1,4 @@
-{ ... }:
+_:

 {
  i18n.defaultLocale = "en_AU.UTF-8";
@@ -15,4 +15,4 @@
    LC_TIME = "en_AU.UTF-8";
  };

-}
+}
@@ -0,0 +1,35 @@
+_:
+
+{
+  # Linode provisions and sizes these disks itself (via the Linode
+  # dashboard/API) before the OS ever boots, and presents them as whole,
+  # unpartitioned block devices — /dev/sda is the root filesystem directly,
+  # /dev/sdb is swap directly, no partition table on either. Nothing here
+  # should ever repartition or resize them:
+  #   - `destroy = false` skips each disk entirely during disko's destroy
+  #     stage (see disko's disk.destroy option) — no wipefs, ever.
+  #   - the filesystem content type's own create step only runs mkfs if the
+  #     device isn't already formatted (checked via `blkid`), so re-running
+  #     this against an already-provisioned Linode disk is a no-op.
+  disko.devices.disk = {
+    main = {
+      device = "/dev/sda";
+      destroy = false;
+
+      content = {
+        type = "filesystem";
+        format = "ext4";
+        mountpoint = "/";
+      };
+    };
+
+    swap = {
+      device = "/dev/sdb";
+      destroy = false;
+
+      content = {
+        type = "swap";
+      };
+    };
+  };
+}
@@ -1,4 +1,4 @@
-{ ... }:
+{ config, vars, ... }:

 {
  disko.devices = {
@@ -6,6 +6,16 @@
      type = "disk";
      device = "/dev/sda";

+      # Only used when building a standalone disk image directly (`nix build
+      # .#nixosConfigurations.<host>.config.system.build.diskoImagesScript`)
+      # rather than formatting a real device — see docs/proxmox-images.md.
+      # imageSize sets the .raw file's total size (root's "100%" below fills
+      # whatever's left after ESP + swap within it); imageName keeps each
+      # host's image distinctly named instead of every proxmox-* host
+      # producing an identical "main.raw".
+      imageSize = vars.proxmoxImageSize;
+      imageName = config.networking.hostName;
+
      content = {
        type = "gpt";

@@ -57,4 +67,4 @@
      };
    };
  };
-}
+}
@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, vars, ... }:

 {
  systemd.services.docker-health-to-gotify = {
@@ -7,9 +7,9 @@
    serviceConfig = {
      Type = "oneshot";
      # Run as root so it can read /etc/secrets and access docker socket
-     # User = "root";
+      # User = "root";
      #EnvironmentFile = "-/etc/secrets/docker-health-alert.env";
-      ExecStart = "${pkgs.bash}/bin/bash /home/nixos/docker/monitoring/gotify/docker-health-to-gotify.sh";
+      ExecStart = "${pkgs.bash}/bin/bash /home/${vars.primaryUser}/docker/monitoring/gotify/docker-health-to-gotify.sh";
      StandardOutput = "journal";
      StandardError = "journal";
    };
@@ -25,4 +25,4 @@
      Persistent = true;
    };
  };
-}
+}
@@ -1,23 +1,23 @@
 { pkgs, ... }:

 {
-    #  virtualisation.docker.enable = true;
+  #  virtualisation.docker.enable = true;
  virtualisation.docker = {
-  enable = true;
-  package = pkgs.docker;
-#  listenOptions = [
-#  "unix:///var/run/docker.sock"
-#  "tcp://0.0.0.0:2375"
-#];
+    enable = true;
+    package = pkgs.docker;
+    #  listenOptions = [
+    #  "unix:///var/run/docker.sock"
+    #  "tcp://0.0.0.0:2375"
+    #];

-#  daemon.settings = {
-#    metrics-addr = "0.0.0.0:9323";
-#    experimental = true;
-#  };
-};
+    #  daemon.settings = {
+    #    metrics-addr = "0.0.0.0:9323";
+    #    experimental = true;
+    #  };
+  };

-environment.systemPackages = with pkgs; [
-  docker-compose
-  docker-buildx
-];
-}
+  environment.systemPackages = with pkgs; [
+    docker-compose
+    docker-buildx
+  ];
+}
@@ -1,63 +1,84 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, vars, ... }:

+let
+  # `x-systemd.automount` never works inside a Linux container (LXC
+  # included, regardless of privilege) -- confirmed live on lxc-docker:
+  # systemd logs "Starting of <unit>.automount unsupported" for every
+  # share and never mounts them. Mount eagerly there instead, with
+  # `nofail` so a boot with the NFS server unreachable doesn't hang
+  # (the VM platforms rely on automount itself to get that same
+  # non-blocking behavior, so they don't need `nofail` too).
+  automountOpts = if config.boot.isContainer then [ "nofail" ] else [ "x-systemd.automount" ];
+
+  # A bare hostname here never resolves reliably: systemd-resolved only
+  # ever tries LLMNR for single-label names (never DNS, regardless of any
+  # configured search domain), and a *global* search domain (the first fix
+  # attempted here) backfires worse -- confirmed live on lxc-docker, adding
+  # `networking.search` made systemd-resolved prioritize its domain-matched
+  # but server-less global scope over eth0's correctly-configured one for
+  # every "*.sweet.home" query, silently sending them to public fallback
+  # DNS instead. `resolvectl query --interface=eth0 server.sweet.home`
+  # resolved fine throughout, proving the LAN DNS server was never the
+  # problem -- only the ambient, unqualified device string was. Using the
+  # FQDN directly sidesteps all of that, matching the pattern
+  # ../raspi/mount-data.nix already uses for the same reason.
+  nfsServer = "${vars.nfsServerHost}.${vars.homeDomain}";
+in
 {
-  fileSystems."/mnt/docker/config" = {
-    device = "server:/tank/docker/config";
-    fsType = "nfs";
+  fileSystems = {
+    ${vars.nfsShares.dockerConfig.mountpoint} = {
+      device = "${nfsServer}:${vars.storageRoot}/${vars.nfsShares.dockerConfig.subpath}";
+      fsType = "nfs";

-    options = [
-      "nfsvers=4.2"
-      "_netdev"
-      "x-systemd.automount"
-      "noatime"
-    ];
-  };
+      options = [
+        "nfsvers=4.2"
+        "_netdev"
+        "noatime"
+      ] ++ automountOpts;
+    };

-  fileSystems."/mnt/docker/databases" = {
-    device = "server:/tank/docker/databases";
-    fsType = "nfs";
+    ${vars.nfsShares.dockerDatabases.mountpoint} = {
+      device = "${nfsServer}:${vars.storageRoot}/${vars.nfsShares.dockerDatabases.subpath}";
+      fsType = "nfs";

-    options = [
-      "nfsvers=4.2"
-      "_netdev"
-      "x-systemd.automount"
-      "noatime"
-    ];
-  };
+      options = [
+        "nfsvers=4.2"
+        "_netdev"
+        "noatime"
+      ] ++ automountOpts;
+    };

-  fileSystems."/mnt/docker/volumes" = {
-    device = "server:/tank/docker/volumes";
-    fsType = "nfs";
+    ${vars.nfsShares.dockerVolumes.mountpoint} = {
+      device = "${nfsServer}:${vars.storageRoot}/${vars.nfsShares.dockerVolumes.subpath}";
+      fsType = "nfs";

-    options = [
-      "nfsvers=4.2"
-      "_netdev"
-      "x-systemd.automount"
-      "noatime"
-    ];
-  };
+      options = [
+        "nfsvers=4.2"
+        "_netdev"
+        "noatime"
+      ] ++ automountOpts;
+    };

- fileSystems."/mnt/nextcloud-data" = {
-    device = "server:/tank/docker/nextcloud-data";
-    fsType = "nfs";
+    ${vars.nfsShares.nextcloudData.mountpoint} = {
+      device = "${nfsServer}:${vars.storageRoot}/${vars.nfsShares.nextcloudData.subpath}";
+      fsType = "nfs";

-    options = [
-      "nfsvers=4.2"
-      "_netdev"
-      "x-systemd.automount"
-      "noatime"
-    ];
-  };
+      options = [
+        "nfsvers=4.2"
+        "_netdev"
+        "noatime"
+      ] ++ automountOpts;
+    };

- fileSystems."/mnt/raspi-backup" = {
-    device = "server:/tank/raspi/volumes";
-    fsType = "nfs";
+    ${vars.nfsShares.raspiVolumes.mountpoint} = {
+      device = "${nfsServer}:${vars.storageRoot}/${vars.nfsShares.raspiVolumes.subpath}";
+      fsType = "nfs";

-    options = [
-      "nfsvers=4.2"
-      "_netdev"
-      "x-systemd.automount"
-      "noatime"
-    ];
+      options = [
+        "nfsvers=4.2"
+        "_netdev"
+        "noatime"
+      ] ++ automountOpts;
+    };
  };
 }
@@ -0,0 +1,22 @@
+{ pkgs, vars, ... }:
+
+{
+  # Create nextcloud cron scheduled task
+  systemd.services.nextcloud = {
+    description = "Nextcloud scheduled task";
+    script = ''${pkgs.bash}/bin/bash ~/docker/services-up.sh --profile nextcloud exec -u 33 nextcloud-webapp php ./cron.php'';
+    serviceConfig = {
+      Type = "oneshot";
+      User = vars.primaryUser;
+    };
+    path = with pkgs; [ docker docker-compose ];
+  };
+
+  systemd.timers.nextcloud = {
+    wantedBy = [ "timers.target" ];
+    timerConfig = {
+      OnCalendar = "*:0/5";
+      Persistent = true;
+    };
+  };
+}
@@ -5,36 +5,39 @@

 {
  imports =
-    [ (modulesPath + "/profiles/qemu-guest.nix")
+    [
+      (modulesPath + "/profiles/qemu-guest.nix")
    ];

-  boot.initrd.availableKernelModules = [ "virtio_pci" "virtio_scsi" "ahci" "sd_mod" ];
-  boot.initrd.kernelModules = [ ];
-  boot.kernelModules = [ ];
-  boot.extraModulePackages = [ ];
-  boot.loader.grub.device = "/dev/sda";
+  boot = {
+    initrd.availableKernelModules = [ "virtio_pci" "virtio_scsi" "ahci" "sd_mod" ];
+    initrd.kernelModules = [ ];
+    kernelModules = [ ];
+    extraModulePackages = [ ];

-  fileSystems."/" =
-    { device = "/dev/sda";
-      fsType = "ext4";
+    # Enable LISH
+    kernelParams = [ "console=ttyS0,19200n8" ];
+
+    loader = {
+      grub = {
+        device = "/dev/sda";
+        extraConfig = ''
+          serial --speed=19200 --unit=0 --word=8 --parity=no --stop=1;
+          terminal_input serial;
+          terminal_output serial;
+        '';
+        forceInstall = true;
+        # device = "nodev";
+      };
+      timeout = 10;
    };
+  };

-  swapDevices =
-    [ { device = "/dev/sdb"; }
-    ];
-
-# Enable LISH
-boot.kernelParams = [ "console=ttyS0,19200n8" ];
-boot.loader.grub.extraConfig = ''
-  serial --speed=19200 --unit=0 --word=8 --parity=no --stop=1;
-  terminal_input serial;
-  terminal_output serial;
-'';
-
-boot.loader.grub.forceInstall = true;
-# boot.loader.grub.device = "nodev";
-boot.loader.timeout = 10;
-
+  # fileSystems."/" and swapDevices are now owned by disko
+  # (../disko/linode.nix, imported from ../platforms/linode.nix) — same
+  # /dev/sda root + /dev/sdb swap layout, declared there instead so disko's
+  # (idempotent, non-destructive — see that file) format/mount scripts stay
+  # in sync with what NixOS actually mounts.

  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
 }
@@ -5,13 +5,16 @@

 {
  imports =
-    [ (modulesPath + "/profiles/qemu-guest.nix")
+    [
+      (modulesPath + "/profiles/qemu-guest.nix")
    ];

-  boot.initrd.availableKernelModules = [ "ata_piix" "uhci_hcd" "virtio_pci" "virtio_scsi" "sd_mod" "sr_mod" ];
-  boot.initrd.kernelModules = [ ];
-  boot.kernelModules = [ "kvm-amd" ];
-  boot.extraModulePackages = [ ];
+  boot = {
+    initrd.availableKernelModules = [ "ata_piix" "uhci_hcd" "virtio_pci" "virtio_scsi" "sd_mod" "sr_mod" ];
+    initrd.kernelModules = [ ];
+    kernelModules = [ "kvm-amd" ];
+    extraModulePackages = [ ];
+  };
  # boot.loader.grub.device = "/dev/sda2"; # or "nodev" for efi only

  # fileSystems."/" =
@@ -0,0 +1,240 @@
+{ pkgs, lib, vars, ... }:
+
+{
+  imports = [
+    ./host-keys.nix
+  ];
+
+  networking.useDHCP = lib.mkDefault true;
+
+  # Recommended over the true default (bypasses ZFS's own import safeguards)
+  # per the option's own docs. This installer environment has no ZFS pools
+  # of its own to import, so this is a no-op here — just silences the
+  # eval-time warning, matching modules/common/configuration.nix.
+  boot.zfs.forceImportRoot = false;
+
+  time.timeZone = vars.timeZone;
+
+  # Without this, the installer only ever sees cache.nixos.org, which
+  # doesn't carry sops-install-secrets (it's built straight from the
+  # sops-nix flake's own Go source, not part of nixpkgs) — every install
+  # would otherwise compile it from scratch, which is what ran an 8GB LXC
+  # container's disk out of space. Push a built copy to nix-cache once
+  # (from a machine with real disk headroom) and every future install,
+  # of any type, fetches instead of rebuilding.
+  nix.settings = {
+    substituters = [
+      "http://nix-cache"
+      "https://cache.nixos.org/"
+    ];
+    trusted-public-keys = [
+      "cache.local-1:usoWYanY3Kpq2+kDIS2nhWoLZiRxanmdysdzqCFBHW4="
+      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
+    ];
+  };
+
+  environment = {
+    systemPackages = with pkgs; [
+      git
+      curl
+      jq
+      parted
+      e2fsprogs
+      btrfs-progs
+      util-linux
+      disko
+    ];
+
+    # Write auto-install script to /root
+    etc."auto-install.sh" = {
+      text = ''
+            #!/run/current-system/sw/bin/bash
+            set -eux
+
+            set -euo pipefail
+
+        export FLAKE_BASE_URL="git+https://${vars.lanDomain}/beatzaplenty/nixos.git"
+
+        echo "Fetching available NixOS hosts from flake..."
+        # Two categories deliberately excluded from the menu:
+        #   lxc-*     — these build a config.system.build.tarball meant for
+        #               `pct restore` on Proxmox directly, not an install.
+        #               Running nixos-install against one here would
+        #               bind-mount / onto /mnt and then refuse to touch the
+        #               filesystem it's currently running on — see
+        #               docs/auto-installer.md.
+        #   installer — this *is* the installer image's own flake target,
+        #               not a deployable host; "installing" it means
+        #               nixos-install-ing a copy of the installer into
+        #               itself.
+        mapfile -t options < <(
+          nix eval --json --no-use-registries --no-accept-flake-config --extra-experimental-features "flakes nix-command" \
+            "''${FLAKE_BASE_URL}#nixosConfigurations" \
+            --apply builtins.attrNames \
+          | jq -r '.[]
+              | select(startswith("lxc-") | not)
+              | select(. != "installer")'
+        )
+
+        if [[ ''${#options[@]} -eq 0 ]]; then
+          echo "ERROR: No NixOS hosts found in ''${FLAKE_BASE_URL}#nixosConfigurations" >&2
+          exit 1
+        fi
+
+        echo "Note: lxc-* targets aren't installed this way — build them with"
+        echo "  nix build .#nixosConfigurations.<name>.config.system.build.tarball"
+        echo "and 'pct restore' the result on Proxmox directly. See docs/auto-installer.md."
+
+        echo "Choose the flake profile to install:"
+        select choice in "''${options[@]}"; do
+          if [[ -n "$choice" ]]; then
+            echo "You selected: $choice"
+            break
+          else
+            echo "Invalid selection. Try again."
+          fi
+        done
+
+        echo "Starting install with flake: ''${FLAKE_BASE_URL}#''${choice}"
+
+        # Optional: confirm before proceeding
+        read -rp "Proceed with installation? (y/N): " confirm
+        if [[ ! "$confirm" =~ ^[Yy]$ ]]; then
+          echo "Aborted."
+          exit 1
+        fi
+
+        # A nix-cache host is *the* substituter/remote-builder for every other
+        # host once installed (its own config explicitly excludes itself from
+        # using either — see buildType != "nix-cache" in the nixos flake.nix).
+        # Installing one shouldn't depend on a nix-cache substituter either,
+        # for the same reason — plus in practice "nix-cache" only resolves over
+        # Tailscale, which a fresh installer environment was never connected to
+        # anyway, so it's dead weight even for non-nix-cache installs until
+        # that's sorted out. Override it away here specifically for nix-cache
+        # targets to keep install-time behaviour consistent with run-time.
+        nix_extra_opts=()
+        if [[ "''${choice}" == *-nix-cache ]]; then
+            echo "Installing a nix-cache host — skipping the nix-cache substituter."
+            nix_extra_opts+=(--option substituters "https://cache.nixos.org/")
+        fi
+
+        # Every host reachable through this menu has a Disko config (lxc-*
+        # is filtered out above, and is the only category that doesn't —
+        # see docs/auto-installer.md), so this can run unconditionally: no
+        # need to probe the flake first and branch on whether Disko applies.
+        disko --mode destroy,format,mount \
+            --flake "''${FLAKE_BASE_URL}#''${choice}" "''${nix_extra_opts[@]}" --yes-wipe-all-disks
+
+        # sops-nix derives this host's decryption key from its own SSH host key
+        # at *activation* time, which runs before systemd would otherwise
+        # generate one on first boot. Without pre-seeding it here, secrets
+        # (including the login password) fail to decrypt on first boot.
+        # Generate the key with scripts/secrets/prepare-host-key.sh first.
+        #
+        # Two places a key can come from, checked in order:
+        #   /etc/host-keys  — baked into this image at build time (see
+        #                      modules/installer/host-keys.nix; only present
+        #                      if built with NIXOS_HOST_KEYS_DIR set)
+        #   /root/host-keys — scp'd in manually after boot (older fallback,
+        #                      still supported for images built without keys)
+        mkdir -p /root/host-keys
+        if [[ -f "/etc/host-keys/''${choice}_ssh_host_ed25519_key" ]]; then
+            echo "Found baked-in SSH host key for ''${choice}, installing to target..."
+            install -D -m 0600 "/etc/host-keys/''${choice}_ssh_host_ed25519_key" /mnt/etc/ssh/ssh_host_ed25519_key
+            install -D -m 0644 "/etc/host-keys/''${choice}_ssh_host_ed25519_key.pub" /mnt/etc/ssh/ssh_host_ed25519_key.pub
+        elif [[ -f "/root/host-keys/''${choice}_ssh_host_ed25519_key" ]]; then
+            echo "Found pre-seeded SSH host key for ''${choice}, installing to target..."
+            install -D -m 0600 "/root/host-keys/''${choice}_ssh_host_ed25519_key" /mnt/etc/ssh/ssh_host_ed25519_key
+            install -D -m 0644 "/root/host-keys/''${choice}_ssh_host_ed25519_key.pub" /mnt/etc/ssh/ssh_host_ed25519_key.pub
+        else
+            echo "WARNING: no SSH host key found for ''${choice} (checked /etc/host-keys and /root/host-keys)"
+            echo "sops-nix secrets (including the login password) will NOT decrypt on first boot."
+            echo "Run scripts/secrets/prepare-host-key.sh for host ''${choice} on your admin workstation first,"
+            echo "then either rebuild this image with NIXOS_HOST_KEYS_DIR set, or scp the result to"
+            echo "/root/host-keys/ on this machine."
+            read -rp "Continue without a pre-seeded key anyway? (y/N): " skip_key
+            if [[ ! "$skip_key" =~ ^[Yy]$ ]]; then
+                echo "Aborted."
+                exit 1
+            fi
+        fi
+
+        mkdir -p /mnt/install-tmp
+        export TMPDIR=/mnt/install-tmp
+
+        nixos-install \
+            --flake "''${FLAKE_BASE_URL}#''${choice}" \
+            "''${nix_extra_opts[@]}" \
+            --no-root-password
+
+
+            rm -rf /mnt/install-tmp
+            # Redundant copy of the host's private key — the real one is now at
+            # /etc/ssh/ssh_host_ed25519_key. Nothing NixOS-managed ever cleans this
+            # up on its own since it was written imperatively, not declaratively.
+            rm -rf /root/host-keys
+            sleep 10
+            reboot
+      '';
+
+      mode = "0755";
+    };
+  };
+
+  programs.git.enable = true;
+
+  # Run the installer on first login. Previously this copied an /etc file
+  # into the nixos user's ~/.bash_profile via an activation script that
+  # got dropped in a refactor (and only ever worked for that one user
+  # anyway) — loginShellInit is NixOS's native hook for this, applies to
+  # any user's login shell (root included), and needs no home-directory
+  # file-copying/chown.
+  programs.bash.loginShellInit = ''
+    if [ -n "$PS1" ] && [ ! -e "$HOME/.auto_install_ran" ]; then
+      sudo /etc/auto-install.sh
+      touch "$HOME/.auto_install_ran"
+    fi
+  '';
+
+  services.openssh.enable = true;
+
+  services.openssh.settings = {
+    PermitRootLogin = "yes";
+    PasswordAuthentication = true;
+  };
+
+  # nixpkgs' own installer profile (profiles/installation-device.nix, pulled
+  # in via installation-cd-minimal.nix) sets initialHashedPassword = "" for
+  # both users — its own passwordless-login convention for install media.
+  # That's a second, non-null password option alongside our hashedPassword
+  # below, which NixOS warns about as ambiguous precedence. Force it null
+  # rather than adopting passwordless login: this image now also boots over
+  # LAN PXE with PasswordAuthentication enabled, so passwordless root SSH
+  # would be reachable by anyone on the LAN, not just local console.
+  users.users.root = {
+    hashedPassword =
+      "$6$Kwv9KAyvcurAViQF$H4.u3feqGE7lVoNgkFXhE3n2Pmo//9JYDTCz8ifrVHBxPjwa1xMby7tEZ8Bpt5MXs9Rkx6/YbZWxs5CpH0s/70";
+    initialHashedPassword = lib.mkForce null;
+  };
+
+  users.users.${vars.primaryUser} = {
+    isNormalUser = true;
+
+    extraGroups = [
+      "wheel"
+    ];
+
+    shell = pkgs.bashInteractive;
+
+    hashedPassword =
+      "$6$Kwv9KAyvcurAViQF$H4.u3feqGE7lVoNgkFXhE3n2Pmo//9JYDTCz8ifrVHBxPjwa1xMby7tEZ8Bpt5MXs9Rkx6/YbZWxs5CpH0s/70";
+    initialHashedPassword = lib.mkForce null;
+
+    openssh.authorizedKeys.keys = [
+      vars.adminSshKey
+    ];
+  };
+
+  system.stateVersion = "26.05";
+}
@@ -0,0 +1,37 @@
+{ lib, ... }:
+
+let
+  # host-keys/ is gitignored (private key material must never be committed),
+  # which means flakes' git-filtered source tree can never see it via a
+  # normal relative path — referencing it at all requires stepping outside
+  # pure evaluation. builtins.getEnv is neutered to "" under normal
+  # `nix build`/`nix eval` (no error, just empty), so this whole module is a
+  # silent no-op unless the operator explicitly opts in with --impure and
+  # the env var set — safe by default, including in CI.
+  #
+  #   NIXOS_HOST_KEYS_DIR=$(pwd)/host-keys nix build .#iso --impure
+  #
+  # See docs/auto-installer.md.
+  hostKeysDirStr = builtins.getEnv "NIXOS_HOST_KEYS_DIR";
+  hasHostKeysDir = hostKeysDirStr != "" && builtins.pathExists hostKeysDirStr;
+  hostKeysDir = /. + hostKeysDirStr;
+
+  keyFileNames =
+    if hasHostKeysDir
+    then
+      lib.filter
+        (name: lib.hasSuffix "_ssh_host_ed25519_key" name || lib.hasSuffix "_ssh_host_ed25519_key.pub" name)
+        (lib.attrNames (builtins.readDir hostKeysDir))
+    else [ ];
+in
+{
+  environment.etc = lib.listToAttrs (map
+    (name: {
+      name = "host-keys/${name}";
+      value = {
+        source = hostKeysDir + "/${name}";
+        mode = "0400";
+      };
+    })
+    keyFileNames);
+}
@@ -0,0 +1,8 @@
+{ modulesPath, ... }:
+
+{
+  imports = [
+    "${modulesPath}/installer/cd-dvd/installation-cd-minimal.nix"
+    ./common.nix
+  ];
+}
@@ -1,9 +1,9 @@
-{ ... }:
+{ vars, ... }:

 {
  nix.settings = {
    substituters = [
-      "http://nix-cache"
+      "http://${vars.nixCacheHost}"
      "https://cache.nixos.org/"
    ];
    trusted-public-keys = [
@@ -0,0 +1,40 @@
+{ pkgs, vars, ... }:
+
+{
+  # Authenticate as nixremote using the client host's own default root SSH
+  # identity (/root/.ssh/id_ed25519) rather than a separately-named key --
+  # matches vars.remoteBuilderAuthorizedKeys, which already authorizes
+  # each host's own default key (one entry per host, not a shared
+  # dedicated keypair). If this host doesn't have one yet:
+  #   sudo -u root ssh-keygen -t ed25519 -N '' -f /root/.ssh/id_ed25519
+  #   # then add its .pub to vars.remoteBuilderAuthorizedKeys and rebuild nix-cache
+  #   sudo ssh -i /root/.ssh/id_ed25519 nixremote@nix-cache nix-store --version
+  # Trust nix-cache's SSH host key declaratively so the nix-daemon (root)
+  # can connect the first time without a manual ssh-keyscan/known_hosts
+  # step on every new client.
+  programs.ssh.knownHosts.${vars.nixCacheHost} = {
+    hostNames = [ vars.nixCacheHost ];
+    publicKey = vars.nixCacheHostKey;
+  };
+
+  nix = {
+    distributedBuilds = true;
+
+    buildMachines = [
+      {
+        hostName = vars.nixCacheHost;
+        sshUser = vars.remoteBuilderUser;
+        sshKey = "/root/.ssh/id_ed25519";
+        inherit (pkgs.stdenv.hostPlatform) system;
+        maxJobs = 4;
+        speedFactor = 2;
+        supportedFeatures = [ "nixos-test" "benchmark" "big-parallel" "kvm" ];
+      }
+    ];
+
+    settings = {
+      builders-use-substitutes = true;
+      max-jobs = "auto";
+    };
+  };
+}
@@ -1,54 +1,53 @@
-{ config, pkgs, ... }:
+{ config, pkgs, vars, ... }:

 {
-  # Generate the binary cache key pair on the nix-cache host:
-  #   sudo install -d -m 0700 /etc/nix
-  #   sudo nix-store --generate-binary-cache-key nix-cache-1 \
-  #     /etc/nix/cache-priv.pem \
-  #     /etc/nix/cache-pub.pem
-  #   sudo chmod 0600 /etc/nix/cache-priv.pem
-  #   sudo chmod 0644 /etc/nix/cache-pub.pem
-  #   cat /etc/nix/cache-pub.pem
-  services.nix-serve = {
-    enable = true;
-    secretKeyFile = "/etc/nix/cache-priv.pem";
-  };
+  # nix-serve's signing key has to be the *same* key on every host that
+  # ever plays the nix-cache role -- modules/nix-cache/client.nix hardcodes
+  # every client's trust in one specific public key ("cache.local-1:..."),
+  # so a freshly self-generated key here wouldn't be trusted by anyone.
+  # Managed via sops-nix like every other secret in this repo instead of
+  # the old manual `nix-store --generate-binary-cache-key` step -- see
+  # "Binary cache signing key" in docs/nix-cache.md for how to add/rotate
+  # the value in secrets/nix-cache.yaml.
+  sops.secrets."cache-priv-key".sopsFile = ../../secrets/nix-cache.yaml;

-  services.nginx = {
-    enable = true;
-    recommendedProxySettings = true;
-    virtualHosts."nix-cache" = {
-      locations."/" = {
-        proxyPass = "http://${config.services.nix-serve.bindAddress}:${toString config.services.nix-serve.port}";
+  services = {
+    nix-serve = {
+      enable = true;
+      secretKeyFile = config.sops.secrets."cache-priv-key".path;
+    };
+
+    nginx = {
+      enable = true;
+      recommendedProxySettings = true;
+      virtualHosts.${vars.nixCacheHost} = {
+        locations."/" = {
+          proxyPass = "http://${config.services.nix-serve.bindAddress}:${toString config.services.nix-serve.port}";
+        };
      };
    };
+
+    openssh.enable = true;
  };

-  networking.firewall.allowedTCPPorts = [ 80 ];
+  networking.firewall.allowedTCPPorts = [ vars.ports.nixCacheHttp ];

-  users.groups.nixremote = {};
+  users.groups.${vars.remoteBuilderUser} = { };

-  users.users.nixremote = {
+  users.users.${vars.remoteBuilderUser} = {
    isSystemUser = true;
-    group = "nixremote";
+    group = vars.remoteBuilderUser;
    createHome = true;
    home = "/var/lib/nixremote";
    shell = pkgs.bashInteractive;
-    # Provide remote builder public keys here (safe to commit public keys only):
-    # openssh.authorizedKeys.keys = [ "ssh-ed25519 AAAA... client@host" ];
-    #
-    # Avoid absolute keyFiles paths here because they break pure flake evaluation.
-    openssh.authorizedKeys.keys = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFDEA1S2ikpObREgbP5uVBWMxIOGbY8B+Wx7VTZK1m6t root@server"
-					"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPAYIT9ormlmxZ0SziyDQaUntnKI8HK9/s3Qac1ZKjP2 root@docker" 
-					"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKKKzoEPl/ZW9KBRHBcp6/ThOngGpwMv5EhkTlgC4aDf root@nixos"
-					"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIGtOWOCS+ImHc7NehguoyD7PbonGosKMZqc9+QR3v/h root@nixos"
-					"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHxXTQxFnArK5HXG7czeoybZebCGfxpUdusJkPn+BCSp root@server"];
+    # Client public keys allowed to use this host as a remote builder —
+    # single source of truth is vars.remoteBuilderAuthorizedKeys (safe to
+    # commit public keys only).
+    openssh.authorizedKeys.keys = vars.remoteBuilderAuthorizedKeys;
  };

-  services.openssh.enable = true;
-
  nix.settings = {
-    trusted-users = [ "root" "nixremote" ];
+    trusted-users = [ "root" vars.remoteBuilderUser ];
    experimental-features = [ "nix-command" "flakes" ];
    auto-optimise-store = true;
    builders-use-substitutes = true;
@@ -57,6 +56,6 @@
  nix.gc = {
    automatic = true;
    dates = "weekly";
-    options = "--delete-older-than 30d";
+    options = "--delete-older-than ${vars.nixCacheGcMaxAge}";
  };
 }
@@ -3,6 +3,7 @@
 {
  imports = [
    ../hardware-configuration/vm/linode.nix
+    ../disko/linode.nix
  ];

  networking = {
@@ -1,8 +1,168 @@
-{ ... }:
+{ config, lib, modulesPath, flakeTarget, ... }:

+let
+  # Bakes this exact flake target's pre-generated SSH host key straight
+  # into /etc/ssh/ -- mirrors modules/installer/host-keys.nix's
+  # builtins.getEnv pattern (impure and empty under normal `nix
+  # build`/`nix eval`, so this is a no-op unless explicitly opted into
+  # with NIXOS_HOST_KEYS_DIR=... --impure), but places the key directly
+  # rather than staging it under /etc/host-keys/ for a later manual copy
+  # -- this is the whole system for a `lxc-*` host, built straight to a
+  # pct-restorable tarball with no install step, so there's no later copy
+  # step to stage for.
+  #
+  # Without this, config.system.build.tarball's built-in system just
+  # generates a fresh host key at first boot like any other host would --
+  # but sops-nix derives its decryption key from *this* file, and
+  # .sops.yaml only trusts whatever key scripts/secrets/sync-host-keys.sh already
+  # registered for this exact target name. A freshly-generated key can
+  # never match that, so every secret (including this host's own login)
+  # permanently fails to decrypt. Confirmed live: sops-install-secrets
+  # errored with "Error getting data key: 0 successful groups required,
+  # got 0" -- the container's actual host key's age fingerprint didn't
+  # match the one registered in .sops.yaml at all.
+  hostKeysDirStr = builtins.getEnv "NIXOS_HOST_KEYS_DIR";
+  hasHostKeysDir = hostKeysDirStr != "" && builtins.pathExists hostKeysDirStr;
+  hostKeysDir = /. + hostKeysDirStr;
+
+  # flakeTarget ("${platform}-${buildType}") comes in via specialArgs from
+  # flake.nix's mkTarget -- exactly the name scripts/secrets/sync-host-keys.sh
+  # registers keys under. Deliberately not read back from
+  # config.environment.etc."flake-target" (which is set to the same value)
+  # -- this module also *contributes* to environment.etc below, and a
+  # module reading the merged value of an option it's still defining is a
+  # circular dependency (confirmed: "infinite recursion encountered").
+  privKeyFile = hostKeysDir + "/${flakeTarget}_ssh_host_ed25519_key";
+  pubKeyFile = hostKeysDir + "/${flakeTarget}_ssh_host_ed25519_key.pub";
+  hasKeyForThisTarget =
+    hasHostKeysDir
+    && builtins.pathExists privKeyFile
+    && builtins.pathExists pubKeyFile;
+in
 {
-  boot.isContainer = true;
+  # LXC containers share the host kernel — Proxmox starts them by exec'ing
+  # /sbin/init directly, no bootloader/initrd involved — and Proxmox has its
+  # own container hostname/network provisioning outside Nix. nixpkgs' own
+  # virtualisation/proxmox-lxc.nix module already handles all of this
+  # correctly (boot.isContainer, loader.initScript, systemd-networkd) and,
+  # critically, provides config.system.build.tarball — a directly
+  # `pct restore`-able container image, no nixos-install/bind-mount needed
+  # (nixos-install refuses to touch the filesystem it's currently running
+  # on, which is exactly what bind-mounting / onto /mnt for an installer
+  # LXC container does).
+  imports = [
+    (modulesPath + "/virtualisation/proxmox-lxc.nix")
+  ];

-  boot.loader.grub.enable = false;
-  boot.loader.systemd-boot.enable = false;
+  proxmoxLXC = {
+    # host.nix declares each host's real hostname (networking.hostName);
+    # keep that instead of letting Proxmox's ambient container config win.
+    manageHostName = true;
+    # Unprivileged by default -- matches how these containers are actually
+    # created (scripts/proxmox/create-proxmox-resource.sh reads this value
+    # back to decide `pct create`'s --unprivileged flag, so the two stay
+    # in sync).
+    #
+    # lxc-docker is the one exception: the kernel's NFS client doesn't set
+    # FS_USERNS_MOUNT, so mounting NFS from inside *any* non-init user
+    # namespace -- which is exactly what an unprivileged container's
+    # UID-mapped root runs in -- is rejected at the VFS layer with EPERM,
+    # no matter what Proxmox's own `mount=nfs;nfs4` container feature
+    # allows at the AppArmor layer (confirmed live: TCP to the NFS server
+    # succeeds, the server's export table matches the container's IP, and
+    # `mount.nfs: Operation not permitted` still fires immediately with no
+    # corresponding denial anywhere in the server's logs -- a kernel-level
+    # rejection, not a network or export-permission one). Keying off
+    # hostName rather than something docker-build-type-specific because
+    # modules/build-types/docker.nix is also composed for linode-docker/
+    # proxmox-docker, which don't import proxmox-lxc.nix at all --setting
+    # this option there would break their eval with "option does not
+    # exist" regardless of any mkIf guard, since mkIf only makes a value
+    # conditional, not whether the option needs to exist somewhere.
+    privileged = config.networking.hostName == "docker";
+  };
+
+  boot.loader = {
+    grub.enable = false;
+    systemd-boot.enable = false;
+  };
+
+  # NetworkManager depends on a running udevd to enumerate/classify devices,
+  # which boot.isContainer disables (see nixpkgs' container-config.nix) —
+  # that's what broke DHCP-hostname registration in Pi-hole. The imported
+  # proxmox-lxc.nix module already switches networking to systemd-networkd
+  # for the same reason; it just doesn't disable NetworkManager itself,
+  # which modules/common/configuration.nix enables for every host.
+  networking.networkmanager.enable = lib.mkForce false;
+
+  environment.etc = lib.mkIf hasKeyForThisTarget {
+    "ssh/ssh_host_ed25519_key" = {
+      source = privKeyFile;
+      mode = "0600";
+    };
+    "ssh/ssh_host_ed25519_key.pub" = {
+      source = pubKeyFile;
+      mode = "0644";
+    };
+  };
+
+  # virtualisation/proxmox-lxc.nix (imported above) registers the Nix
+  # store DB via a systemd service (register-nix-paths) -- it never runs
+  # an activation script at all. Confirmed live this means neither
+  # sops-nix's "for users" secrets (password hashes -- installed by the
+  # activation script itself, not a systemd service, since they need to
+  # exist *before* user creation) nor the user-creation step that
+  # consumes them ever run on a real lxc-* boot. Regular secrets
+  # (nix-serve's key, beszel's token, etc.) work anyway because sops-nix
+  # provides its own systemd service for those.
+  #
+  # A systemd service, not boot.postBootCommands: tried that first (it's
+  # a genuine, generally-invoked hook -- nixos/modules/system/boot/stage-2-init.sh,
+  # which becomes this container's actual /sbin/init, unconditionally
+  # runs it) but switch-to-configuration behaves differently that early in
+  # boot (raw stage-2-init.sh, before systemd itself has even started) --
+  # confirmed live it silently failed to rewrite /etc/shadow from there
+  # even in "test" mode, despite the exact same command working reliably
+  # every time when run post-boot (i.e. as a normal systemd service, which
+  # is what this is). Not fully root-caused why the early context
+  # specifically breaks it; a real systemd service sidesteps needing to.
+  #
+  # /etc/shadow already has PLACEHOLDER entries for every declared user
+  # baked in at build time (part of constructing the system closure).
+  # update-users-groups.pl deliberately never overwrites an *existing*
+  # shadow entry -- a correct safety property in general (don't clobber a
+  # real user's real password on a config rebuild) -- but on a genuine
+  # first boot that only means the real hashedPasswordFile-derived hash
+  # never gets the chance to be applied either, since the placeholder is
+  # already "seen". Safe to clear here specifically: there is no real
+  # password yet to protect on a first boot.
+  #
+  # "test" mode, not "boot": confirmed live "boot" mode aborts partway
+  # through (before rewriting /etc/shadow) on a warning that "/boot" is on
+  # a different filesystem -- a real check for a host with a bootloader to
+  # update, meaningless for a container that has none
+  # (boot.loader.{grub,systemd-boot}.enable are both false above), but it
+  # still aborts the script. "test" runs every activation step without
+  # touching boot-loader state at all.
+  #
+  # ConditionPathExists (systemd-native, not a bash-level check) means
+  # this only ever runs once, on the genuine first boot -- systemd itself
+  # skips even starting it on every later boot once the marker exists.
+  # switch-to-configuration is otherwise the operator's call per this
+  # repo's own safety rules, not something to run on every boot.
+  systemd.services.nixos-lxc-first-boot-activate = {
+    description = "Complete first-boot NixOS activation (users, secrets) for this LXC container";
+    wantedBy = [ "multi-user.target" ];
+    unitConfig.ConditionPathExists = "!/var/lib/nixos-lxc-first-boot-activated";
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+    };
+    script = ''
+      rm -f /etc/shadow
+      /run/current-system/bin/switch-to-configuration test
+      mkdir -p /var/lib
+      touch /var/lib/nixos-lxc-first-boot-activated
+    '';
+  };
 }
@@ -0,0 +1,32 @@
+{ netbootSystem, netbootMinimalSystem, ... }:
+
+let
+  # config.system.build.kernel and .netbootRamdisk are directories, not the
+  # files themselves — nixpkgs' own system.build.kexecTree does the same
+  # ${...}/<file> dereference for the same reason.
+  mkStageRules = { dirName, system }:
+    let
+      inherit (system.config.system.boot.loader) kernelFile;
+      dir = "/srv/pxe/http/${dirName}";
+    in
+    [
+      # Declared here too (not just in build-types/pxe-boot.nix) so this
+      # module's C+ rules don't depend on cross-module list-merge ordering —
+      # tmpfiles' C type needs the target directory to already exist.
+      "d ${dir} 0755 root root -"
+      "C+ ${dir}/${kernelFile} 0644 root root - ${system.config.system.build.kernel}/${kernelFile}"
+      "C+ ${dir}/initrd 0644 root root - ${system.config.system.build.netbootRamdisk}/initrd"
+      "C+ ${dir}/netboot.ipxe 0644 root root - ${system.config.system.build.netbootIpxeScript}/netboot.ipxe"
+    ];
+in
+{
+  # Builds this flake's own installer netboot image (the same one
+  # `nix build .#pxe` produces) plus the vanilla NixOS minimal netboot image
+  # (`nix build .#pxe-minimal`), and stages both where menu.ipxe's
+  # :auto-installer / :nixos-minimal entries expect them, so the pxe-boot
+  # host is self-contained — no manual operator step to populate
+  # /srv/pxe/http after deploy.
+  systemd.tmpfiles.rules =
+    mkStageRules { dirName = "auto-installer"; system = netbootSystem; }
+    ++ mkStageRules { dirName = "nixos-minimal"; system = netbootMinimalSystem; };
+}
@@ -1,26 +1,32 @@
-{ ... }:
+{ config, lib, vars, ... }:

 {
-fileSystems."/mnt/raspi" = {
-  device = "raspberrypi.tail13f623.ts.net:/home/raspi/raspi";
-  fsType = "nfs4";
-  options = [
-    "nofail"
-    "_netdev"
-    "noatime"
+  fileSystems.${vars.raspiMountpoint} = {
+    device = "${vars.raspberryPiHost}.${vars.tailnetDomain}:${vars.raspiNfsPath}";
+    fsType = "nfs4";
+    options = [
+      "nofail"
+      "_netdev"
+      "noatime"

-    # Don't mount until first access
-    "x-systemd.automount"
+      # Explicitly use NFSv4.2 if supported
+      "nfsvers=4.2"
+    ] ++ lib.optionals (!config.boot.isContainer) [
+      # `x-systemd.automount` never works inside a Linux container (LXC
+      # included) -- confirmed live on lxc-docker: systemd logs "Starting
+      # of <unit>.automount unsupported" and never mounts it. `nofail`
+      # above already keeps boot non-blocking there, so plain eager
+      # mounting is fine.

-    # Unmount after 10 min idle
-    "x-systemd.idle-timeout=600"
+      # Don't mount until first access
+      "x-systemd.automount"

-    # Give the Pi/Tailscale a little time to appear
-    "x-systemd.device-timeout=10s"
+      # Unmount after 10 min idle
+      "x-systemd.idle-timeout=600"

-    # Explicitly use NFSv4.2 if supported
-    "nfsvers=4.2"
-  ];
-};
+      # Give the Pi/Tailscale a little time to appear
+      "x-systemd.device-timeout=10s"
+    ];
+  };

-}
+}
@@ -1,26 +0,0 @@
-{ pkgs, ... }:
-
-{
-  # Install the remote builder key on each client host (do not commit private keys):
-  #   sudo install -d -m 0700 /root/.ssh
-  #   sudo install -m 0600 ./nixremote /root/.ssh/nixremote
-  #   sudo ssh -i /root/.ssh/nixremote nixremote@nix-cache nix-store --version
-  nix.distributedBuilds = true;
-
-  nix.buildMachines = [
-    {
-      hostName = "nix-cache";
-      sshUser = "nixremote";
-      sshKey = "/root/.ssh/nixremote";
-      system = pkgs.stdenv.hostPlatform.system;
-      maxJobs = 4;
-      speedFactor = 2;
-      supportedFeatures = [ "nixos-test" "benchmark" "big-parallel" "kvm" ];
-    }
-  ];
-
-  nix.settings = {
-    builders-use-substitutes = true;
-    max-jobs = "auto";
-  };
-}
@@ -1,20 +0,0 @@
-{ ... }:
-
-{
-      services.logrotate = {
-    enable = true;
-
-    settings = {
-      "/mnt/docker/volumes/traefik-data/logs/*.log" = {
-        daily = true;
-        size = "100M";
-        rotate = 20;
-        compress = true;
-        missingok = true;
-        notifempty = true;
-        copytruncate = true;
-      };
-
-     };
-  };
-}
@@ -1,5 +1,5 @@
- { ... }:
- 
- {
- services.rpcbind.enable = true;
- }
+_:
+
+{
+  services.rpcbind.enable = true;
+}
@@ -1,22 +0,0 @@
-{ pkgs, ... }:
-
-{
-# Create nextcloud cron scheduled task
-systemd.services.nextcloud = {
-  description = "Nextcloud scheduled task";
-  script = ''${pkgs.bash}/bin/bash ~/docker/services-up.sh --profile nextcloud exec -u 33 nextcloud-webapp php ./cron.php'';
-  serviceConfig = {
-    Type = "oneshot";
-    User = "nixos";
-  };
-  path = with pkgs; [ docker docker-compose ];
-};
-
-systemd.timers.nextcloud = {
-  wantedBy = [ "timers.target" ];
-  timerConfig = {
-    OnCalendar = "*:0/5";
-    Persistent = true;
-  };
-};
-}
@@ -1,12 +1,12 @@
 { pkgs, boot, ... }:

 {
-boot.postBootCommands = ''
-  echo "=== STARTING ZPOOL IMPORT ==="
-  ${pkgs.zfs_unstable}/bin/zpool import -a -N -d /dev/disk/by-path
-  ${pkgs.zfs_unstable}/bin/zpool status
-  ${pkgs.zfs_unstable}/bin/zfs mount -a
-  ${pkgs.zfs_unstable}/bin/zfs list
-    echo "=== ZPOOL IMPORT COMPLETE ==="
-'';
- }
+  boot.postBootCommands = ''
+    echo "=== STARTING ZPOOL IMPORT ==="
+    ${pkgs.zfs_unstable}/bin/zpool import -a -N -d /dev/disk/by-path
+    ${pkgs.zfs_unstable}/bin/zpool status
+    ${pkgs.zfs_unstable}/bin/zfs mount -a
+    ${pkgs.zfs_unstable}/bin/zfs list
+      echo "=== ZPOOL IMPORT COMPLETE ==="
+  '';
+}
@@ -1,16 +1,21 @@
 { pkgs, ... }:

- {
-boot.supportedFilesystems = [ "zfs" ];
-  boot.zfs.forceImportRoot = false;
-  boot.zfs.package = pkgs.zfs_unstable;
-      services.zfs = {
+{
+  boot = {
+    supportedFilesystems = [ "zfs" ];
+    zfs = {
+      forceImportRoot = false;
+      package = pkgs.zfs_unstable;
+      devNodes = "/dev/disk/by-id";
+    };
+  };
+
+  services.zfs = {
    autoScrub.enable = true;
    autoSnapshot.enable = true;
    trim.enable = true;
  };

-#systemd.services.zfs-import-cache.enable = true;
-systemd.services.zfs-mount.enable = true;
-boot.zfs.devNodes = "/dev/disk/by-id";
- }
+  #systemd.services.zfs-import-cache.enable = true;
+  systemd.services.zfs-mount.enable = true;
+}
@@ -1,5 +1,5 @@
-{ ... }:
+_:

 {
-    services.tailscale.enable = true;
-}
+  services.tailscale.enable = true;
+}
@@ -1,12 +1,27 @@
-{ ... }:
+_:

 {
-  services.tailscale = {
-    enable = true;
+  imports = [ ./enable-service.nix ];

-    extraUpFlags = [
+  services.tailscale = {
+    # Enables the sysctl forwarding settings exit nodes/subnet routers need;
+    # without this, --advertise-exit-node has no effect.
+    useRoutingFeatures = "server";
+
+    # Lets peers reach this node directly over the tailscale UDP port
+    # instead of relaying through DERP.
+    openFirewall = true;
+
+    # extraSetFlags (tailscale set, via the always-on tailscaled-set
+    # service), not extraUpFlags -- extraUpFlags is only ever applied by
+    # tailscaled-autoconnect, which itself only runs when
+    # services.tailscale.authKeyFile is set (nothing in this repo sets one,
+    # so tailscale up is a manual, one-time operator step on every host that
+    # uses this service). extraSetFlags has no such gate, so
+    # --advertise-exit-node self-reapplies on every boot once the operator
+    # has authenticated the node once.
+    extraSetFlags = [
      "--advertise-exit-node"
-      "--advertise-routes=192.168.2.0/24"
    ];
  };
 }
@@ -0,0 +1,35 @@
+{ pkgs, vars, ... }:
+
+{
+  services.tor = {
+    enable = true;
+
+    # Opens settings.ORPort (and DirPort, unset here) in the firewall —
+    # see the nixpkgs tor module's own networking.firewall.mkIf block.
+    openFirewall = true;
+
+    relay = {
+      enable = true;
+      # Plain middle/guard relay, not "exit" — relays onion traffic between
+      # other Tor nodes without ever making requests to the public internet
+      # on a user's behalf, avoiding the abuse complaints and legal exposure
+      # an exit node invites.
+      role = "relay";
+    };
+
+    settings.ORPort = vars.ports.torRelayOrPort;
+
+    # Unix control socket at /run/tor/control (GroupWritable, group "tor")
+    # -- what nyx below actually monitors the relay through. Nyx's own
+    # default control-socket path (/var/run/tor/control) resolves to the
+    # same place, so no extra nyx config is needed.
+    controlSocket.enable = true;
+  };
+
+  # Lets the primary user's shell session read/write the control socket
+  # above without being root -- otherwise nyx fails to authenticate against
+  # it at all.
+  users.users.${vars.primaryUser}.extraGroups = [ "tor" ];
+
+  environment.systemPackages = [ pkgs.nyx ];
+}
@@ -0,0 +1,20 @@
+{ vars, ... }:
+
+{
+  services.logrotate = {
+    enable = true;
+
+    settings = {
+      "${vars.nfsShares.dockerVolumes.mountpoint}/traefik-data/logs/*.log" = {
+        daily = true;
+        size = vars.traefikLogRotate.maxSize;
+        rotate = vars.traefikLogRotate.keep;
+        compress = true;
+        missingok = true;
+        notifempty = true;
+        copytruncate = true;
+      };
+
+    };
+  };
+}
@@ -1,30 +0,0 @@
-#create MBR table
-parted /dev/sda -- mklabel msdos
-#create nixos partition
-parted /dev/sda -- mkpart primary 1MB -8GB
-#set nixos partition to bootable
-parted /dev/sda -- set 1 boot on
-# create swap partition
-parted /dev/sda -- mkpart primary linux-swap -8GB 100%
-
-#format OS partition
-mkfs.ext4 -L nixos /dev/sda1
-#format swap
-mkswap -L swap /dev/sda2
-
-#activate swap
-swapon /dev/sda2
-
-#mount nixos partition
-mount /dev/disk/by-label/nixos /mnt
-export TMPDIR=/mnt/install-tmp
-mkdir -p /mnt/install-tmp
-#Generate config
-#nixos-generate-config --root /mnt/
-
-#copy customised configuration over
-#cp configuration.nix /mnt/etc/nixos/configuration.nix
-
-#nixos-install --no-root-passwd
-
-#reboot
@@ -1,134 +0,0 @@
-# Spec: Remove Sensitive Information from NixOS Flake
-
-## Goal
-
-Every secret currently readable in plaintext anywhere in this repo (working tree *and* git history) gets removed, replaced with `sops-nix`-managed encrypted references, and rotated. When this is done, the repo should be safe to make public without exposing anything about the systems it configures.
-
-Treat this as three sequential milestones. Do not start git history rewriting (Milestone 3) until Milestones 1 and 2 are fully verified and the flake still builds. This should be its own branch (`refactor/secrets`) until fully verified, then merged.
-
---
-
-## Milestone 1 — Audit
-
-Before touching anything, produce a complete inventory. Do not guess at scope — grep the whole tree and the whole history.
-
-1. Run a secret scanner across the working tree and full history. Use both, since they catch different things:
-   - `gitleaks detect --source . -v --log-opts="--all"` (scans history too)
-   - `trufflehog git file://. --since-commit=$(git rev-list --max-parents=0 HEAD) --only-verified=false`
-   If neither is installed, add them via a temporary `nix-shell -p gitleaks trufflehog` — don't install anything globally on the host.
-
-2. Manually grep for the categories below, since scanners miss config-specific patterns:
-   - `hashedPassword`, `password`, `initialPassword`, `initialHashedPassword` in any `users.users.*` block
-   - `age.secrets`, `sops.secrets` (if any partial secrets work already exists — check for it)
-   - PSK / `preSharedKey`, `privateKeyFile` inline values (vs. file references) for WireGuard
-   - `authKey`, `apiToken`, `api_key`, `token =`, `secret =` in service modules (Tailscale, Cloudflare, backup tools, etc.)
-   - SSH private key material: search for `BEGIN OPENSSH PRIVATE KEY` / `BEGIN RSA PRIVATE KEY` literals
-   - TLS cert/key pairs committed under e.g. `secrets/`, `certs/`, `pki/`
-   - Real name, personal email, home address, or anything in comments/hostnames that maps a machine to your physical identity or network layout (e.g. hostnames like `wayne-desktop`, static LAN IPs, ISP-identifying info)
-   - `.env` files, `secrets.nix`, `secrets.yaml`, or any file that looks like it was meant to be gitignored but wasn't
-
-3. Produce `secrets-inventory.md` (temporary, delete before finishing) listing: file path, line, secret type, and which host/service it belongs to. This becomes the checklist for Milestone 2 — every row must be either migrated to sops or deleted, with nothing left unaccounted for.
-
---
-
-## Milestone 2 — Migrate to sops-nix
-
-### 2.1 Set up sops-nix
-
-1. Add the flake input:
-   ```nix
-   sops-nix.url = "github:Mic92/sops-nix";
-   sops-nix.inputs.nixpkgs.follows = "nixpkgs";
-   ```
-2. Import `sops-nix.nixosModules.sops` into each host's module list (or into a shared `common.nix` if all hosts use it).
-3. Generate an age keypair **per host** (not one shared key for everything — a compromised host shouldn't decrypt every other host's secrets):
-   ```
-   nix-shell -p age --run "age-keygen -o /var/lib/sops-nix/key.txt"
-   ```
-   Print the public key (`age-keygen -y`) for each host — you'll need it for `.sops.yaml`.
-4. Also generate one age key for yourself (your admin workstation) so you can edit secrets without needing to SSH into a host: store it at `~/.config/sops/age/keys.txt`, back it up somewhere outside this repo (password manager, offline). **If this key is lost, every secret encrypted with it is unrecoverable — losing the age key is equivalent to losing the secrets.**
-5. Create `.sops.yaml` at the repo root defining creation rules: which age public keys can decrypt which secrets files, keyed by path regex, so e.g. `secrets/hostA.yaml` is decryptable by your admin key + hostA's key, `secrets/hostB.yaml` by your admin key + hostB's key.
-
-### 2.2 Migrate each secret category from the inventory
-
-For each row in `secrets-inventory.md`:
-
- **Password hashes**: generate hash with `mkpasswd -m sha-512` (or `bcrypt` if your setup wants that), store under `sops.secrets."<name>/hashedPassword"`, reference via `users.users.<name>.hashedPasswordFile = config.sops.secrets."<name>/hashedPassword".path;`. Do not put the *plaintext* password anywhere, only the hash, and only the hash goes into the encrypted sops file.
- **API tokens / auth keys**: move the raw value into the per-host sops YAML, reference in the module via `config.sops.secrets."<service>/token".path` — most NixOS service modules that take a token also accept a `*File` variant (e.g. `environmentFile`, `tokenFile`); use that instead of passing the value directly.
- **Private keys / certs**: move the PEM/key content wholesale into a sops secret, output as a file with appropriate `sops.secrets.<name>.path`, `owner`, `mode`, `restartUnits` so the depending service (sshd, wireguard, nginx) reloads when the secret changes.
- **Personal/identifying info**: this doesn't belong in sops (it's not "secret," it's just information you don't want public). Replace real names/emails with placeholders or move to a small untracked `local.nix` that's `.gitignore`'d and imported conditionally, with a documented template (`local.nix.example`) committed instead.
-
-### 2.3 Verify before moving on
-
- `nixos-rebuild dry-build --flake .#<host>` succeeds for every host.
- `sudo nixos-rebuild switch --flake .#<host>` on at least one real machine (or a VM) confirms secrets decrypt and services start.
- Confirm decrypted secrets land under `/run/secrets/` (not the Nix store — anything placed in `/nix/store` is world-readable by design, so sops-nix's runtime-only placement is the whole point; double check no module accidentally pulls a secret path into a store-built config file).
- Re-run the grep/scanner sweep from Milestone 1 against the *working tree only* (not history yet) — it should now come back clean.
-
---
-
-## Milestone 3 — Scrub git history
-
-Do this only after Milestone 2 is merged to your main branch and confirmed working, since it rewrites every commit SHA from the point of the earliest offending commit onward.
-
-**This is destructive and irreversible on your local clone. Back up first:**
-```
-cp -r /path/to/nixos-repo /path/to/nixos-repo-backup-$(date +%F)
-```
-
-1. Install `git-filter-repo` (not the older `git filter-branch` / BFG — filter-repo is the currently maintained, faster, safer tool):
-   ```
-   nix-shell -p git-filter-repo
-   ```
-2. Use the `secrets-inventory.md` list to build a list of literal strings/paths to strip. Two approaches, use both:
-   - Path-based: if whole files were secret (e.g. `secrets.nix`, a `.env`, a private key file), remove them entirely from history:
-     ```
-     git filter-repo --path secrets.nix --path .env --invert-paths
-     ```
-   - Value-based: for secrets embedded inline in files you're keeping (not deleting the whole file), use `--replace-text` with a file listing each literal secret string to replace with `***REMOVED***`:
-     ```
-     git filter-repo --replace-text expressions.txt
-     ```
-3. After filtering, verify: run the Milestone 1 scanners again against full history (`--log-opts="--all"`). They must come back clean.
-4. Force-push the rewritten history:
-   ```
-   git push origin --force --all
-   git push origin --force --tags
-   ```
-5. **Every other clone of this repo (other machines, WSL instances, CI) must be deleted and re-cloned fresh** — a `git pull` against rewritten history will not work cleanly and risks resurrecting the old commits. Don't try to reconcile old clones; throw them away and re-clone.
-6. If this repo has ever been pushed to a public host (GitHub, etc.) or a fork/mirror exists, treat every secret that was ever in history as **permanently compromised regardless of the rewrite** — caches, forks, and Wayback-style archives can retain old commits indefinitely. History scrubbing prevents *future* exposure via `git clone`; it does not undo past exposure.
-
---
-
-## Milestone 4 — Rotate everything
-
-Because the secrets were exposed in history (even briefly, even in a private repo), the migration is not complete until every credential in the inventory has been **rotated**, not just re-encrypted. Re-encrypting an already-leaked value protects it going forward but doesn't undo the leak.
-
-For each row in the original inventory:
- Password hashes → change the actual account password, regenerate the hash, update the sops file.
- API tokens/auth keys → revoke the old token in the issuing service's dashboard (Cloudflare, Tailscale, backup provider, etc.) and generate a new one.
- SSH/WireGuard private keys → generate new keypairs, update the corresponding public key wherever it's trusted (authorized_keys, peer configs, etc.), retire the old ones.
- TLS certs → reissue if the private key was exposed.
-
-Keep `secrets-inventory.md` open during this step and check off each row as rotated. Delete the file only once every row is checked off — it should not be committed.
-
---
-
-## Ongoing prevention
-
-Add a pre-commit hook (or a `nix flake check` step) running `gitleaks protect --staged` so a secret can't be committed again by accident. Document in the repo README (briefly) that new secrets go through `sops <file>` to edit, never as plaintext in a tracked file.
-
---
-
-## Definition of done
-
- [ ] Milestone 1 inventory complete and reviewed
- [ ] All hosts have per-host age keys; admin key backed up outside the repo
- [ ] Every inventoried secret migrated to sops-nix, referenced via `*File`/`sops.secrets.*.path`, nothing plaintext in the working tree
- [ ] `nixos-rebuild dry-build` and at least one real `switch` verified per host
- [ ] Working-tree scanner sweep clean
- [ ] History rewritten with `git-filter-repo`, force-pushed, full-history scanner sweep clean
- [ ] All other clones deleted and re-cloned from the rewritten history
- [ ] Every credential in the original inventory rotated (not just re-encrypted)
- [ ] Pre-commit secret scanning hook added
- [ ] `secrets-inventory.md` deleted from the working directory (never committed)
@@ -0,0 +1,134 @@
+#!/usr/bin/env bash
+# Bumps the NixOS release branch this flake tracks — flake.nix's
+# `nixpkgs.url` and `home-manager.url` — in one place, via targeted
+# substitution of just those two lines. Deliberately does NOT touch any
+# `system.stateVersion` anywhere in the repo: per NixOS's own docs, that
+# value must stay fixed at whatever it was on a host's first install (it
+# pins on-disk data-format defaults, not "which nixpkgs release am I on"),
+# so it's never something a channel bump should follow.
+#
+# scripts/codex-maintenance.sh's own `nixos-25.11` pin (used only to fetch
+# nixpkgs-fmt/statix — see CLAUDE.md) is a separate, independently-versioned
+# reference on purpose: it doesn't have to track the flake's own nixpkgs
+# input, since the tooling just needs to build, not match. Bump it with
+# --tooling if you want it moved too; the default run leaves it alone.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/.." && pwd)"
+flake_nix="${repo_root}/flake.nix"
+maintenance_sh="${repo_root}/scripts/codex-maintenance.sh"
+claude_md="${repo_root}/CLAUDE.md"
+
+usage() {
+  cat <<EOF
+Usage: $0 <release> [--tooling <release>]
+
+  <release>            New NixOS release for flake.nix's nixpkgs.url and
+                        home-manager.url, e.g. 26.11
+  --tooling <release>  Also bump scripts/codex-maintenance.sh's separate
+                        nixpkgs-fmt/statix pin (and its mention in
+                        CLAUDE.md) to this release. Independent of the
+                        first argument — pass the same value if you want
+                        both in sync, a different one if you don't.
+
+Examples:
+  $0 26.11
+  $0 26.11 --tooling 26.11
+EOF
+}
+
+release_re='^[0-9]{2}\.(05|11)$'
+
+if [[ $# -eq 0 || "$1" == "-h" || "$1" == "--help" ]]; then
+  usage
+  exit 0
+fi
+
+new_release="$1"
+shift
+
+tooling_release=""
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+  --tooling)
+    tooling_release="${2:?--tooling requires a release argument}"
+    shift 2
+    ;;
+  *)
+    echo "Unknown argument: $1" >&2
+    usage >&2
+    exit 1
+    ;;
+  esac
+done
+
+check_release_format() {
+  local release="$1"
+  if [[ ! "$release" =~ $release_re ]]; then
+    echo "ERROR: '$release' doesn't look like a NixOS release (expected e.g. 26.11)" >&2
+    exit 1
+  fi
+}
+
+check_branch_exists() {
+  local repo_url="$1" branch="$2"
+  echo "Checking '$branch' exists on $repo_url..."
+  if ! git ls-remote --exit-code --heads "$repo_url" "$branch" >/dev/null; then
+    echo "ERROR: branch '$branch' not found on $repo_url. Typo, or not cut yet?" >&2
+    exit 1
+  fi
+}
+
+check_release_format "$new_release"
+
+current_release="$(grep -oE 'nixos-[0-9]{2}\.[0-9]{2}' "$flake_nix" | head -1 | sed 's/^nixos-//')"
+if [[ -z "$current_release" ]]; then
+  echo "ERROR: couldn't find flake.nix's current nixpkgs release" >&2
+  exit 1
+fi
+
+if [[ "$current_release" == "$new_release" ]]; then
+  echo "flake.nix is already on $new_release."
+else
+  echo "Bumping flake.nix's nixpkgs/home-manager release: $current_release -> $new_release"
+  check_branch_exists "https://github.com/NixOS/nixpkgs.git" "nixos-$new_release"
+  check_branch_exists "https://github.com/nix-community/home-manager.git" "release-$new_release"
+
+  sed -i \
+    -e "s|github:NixOS/nixpkgs/nixos-${current_release}|github:NixOS/nixpkgs/nixos-${new_release}|" \
+    -e "s|github:nix-community/home-manager/release-${current_release}|github:nix-community/home-manager/release-${new_release}|" \
+    "$flake_nix"
+
+  echo "Updated:"
+  grep -n "nixos-${new_release}\|release-${new_release}" "$flake_nix"
+fi
+
+if [[ -n "$tooling_release" ]]; then
+  check_release_format "$tooling_release"
+
+  current_tooling_release="$(grep -oE 'nixos-[0-9]{2}\.[0-9]{2}' "$maintenance_sh" | head -1 | sed 's/^nixos-//')"
+
+  if [[ "$current_tooling_release" == "$tooling_release" ]]; then
+    echo "codex-maintenance.sh's tooling pin is already on $tooling_release."
+  else
+    echo "Bumping codex-maintenance.sh's nixpkgs-fmt/statix pin: $current_tooling_release -> $tooling_release"
+    check_branch_exists "https://github.com/NixOS/nixpkgs.git" "nixos-$tooling_release"
+
+    sed -i "s|github:NixOS/nixpkgs/nixos-${current_tooling_release}|github:NixOS/nixpkgs/nixos-${tooling_release}|g" \
+      "$maintenance_sh"
+    sed -i "s|nixos-${current_tooling_release}|nixos-${tooling_release}|g" \
+      "$claude_md"
+
+    echo "Updated:"
+    grep -n "nixos-${tooling_release}" "$maintenance_sh" "$claude_md"
+  fi
+fi
+
+echo
+echo "flake.lock still points at the old input revisions until refreshed. Either:"
+echo "  nix flake update nixpkgs home-manager   # just these two inputs"
+echo "  nix flake update                        # everything — see docs/flake-lock-automation.md"
+echo
+echo "Then run 'bash scripts/codex-maintenance.sh --full-check --dry-run' before"
+echo "committing — a channel bump can shift option defaults across every host,"
+echo "and only --dry-run actually builds anything to catch that."
@@ -1,22 +1,63 @@
 #!/usr/bin/env bash
+# Validation entry point for CI and local/agent review.
+#
+# Default mode (what CI runs on every push/PR): fmt-check, statix, and eval
+# are scoped to files that actually changed against a base ref, plus
+# whichever hosts/packages those changes can affect. This exists because
+# the unscoped sweep below is slow enough to time out CI runners -- see
+# --full-check.
+#
+# --full-check: the historical full sweep (every host, every package,
+# fmt --check ./statix check . over the whole tree). Slow -- minutes, not
+# seconds. CI never passes this; run it locally before a release or after
+# touching modules/common/*, flake.nix, or variables.nix if you want extra
+# confidence beyond what the changed-files scope already covers for those
+# paths (see below).
+#
+# --dry-run: adds `nix build --dry-run --no-link` for whatever scope is
+# active (changed-files scope by default, full scope under --full-check).
 set -euo pipefail

-export NIX_CONFIG="${NIX_CONFIG:-}
-experimental-features = nix-command flakes
-accept-flake-config = false
-warn-dirty = false
-"
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=lib/nix-bootstrap.sh
+source "${script_dir}/lib/nix-bootstrap.sh"
+# shellcheck source=lib/nix-eval.sh
+source "${script_dir}/lib/nix-eval.sh"

-MODE="${1:-validate}"
+repo_root="$(cd "${script_dir}/.." && pwd)"
+cd "$repo_root"

-ensure_nix_profile() {
-  if [ -f /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh ]; then
-    . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
-  elif [ -f "$HOME/.nix-profile/etc/profile.d/nix.sh" ]; then
-    . "$HOME/.nix-profile/etc/profile.d/nix.sh"
-  fi
+full_check=false
+dry_run=false
+
+usage() {
+  cat <<'EOF'
+Usage: scripts/codex-maintenance.sh [--full-check] [--dry-run]
+
+  --full-check  Run the full sweep: fmt-check and statix over the whole
+                repo, eval every host and package. Slow. Never run by CI.
+  --dry-run     Additionally run `nix build --dry-run --no-link` for
+                whatever scope is active.
+
+With neither flag (the CI default), fmt-check/statix/eval are scoped to
+files changed against a base ref (env MAINT_BASE_SHA, else the PR base,
+else HEAD^), plus the hosts/packages those changes can affect.
+EOF
 }

+for arg in "$@"; do
+  case "$arg" in
+    --full-check) full_check=true ;;
+    --dry-run) dry_run=true ;;
+    -h|--help) usage; exit 0 ;;
+    *)
+      echo "Unknown argument: $arg" >&2
+      usage >&2
+      exit 1
+      ;;
+  esac
+done
+
 ensure_nix_profile

 if ! command -v nix >/dev/null 2>&1; then
@@ -24,13 +65,6 @@ if ! command -v nix >/dev/null 2>&1; then
  exit 127
 fi

-hosts_json="$(nix eval --json --no-use-registries --no-accept-flake-config .#nixosConfigurations --apply builtins.attrNames)"
-hosts="$(echo "$hosts_json" | jq -r '.[]')"
-
-echo "Hosts:"
-echo "$hosts"
-
-echo
 echo "Checking for obvious committed secrets..."
 if grep -RInE 'github_pat_|ghp_|access-tokens|hashedPassword[[:space:]]*=' \
  --exclude-dir=.git \
@@ -42,29 +76,238 @@ else
  echo "No obvious token patterns found."
 fi

+mapfile -t all_hosts < <(list_flake_targets .)
+mapfile -t all_packages < <(nix eval --json "${NIX_EVAL_FLAGS[@]}" .#packages.x86_64-linux --apply builtins.attrNames | jq -r '.[]')
+
+# host_targets_for_dir <hosts-subdir-name>
+# Prints the nixosConfigurations target names whose hostPath is
+# ./hosts/<dir>/host.nix, derived straight from flake.nix's generatedTargets
+# (one mkTarget { ... } call per line) rather than a hand-maintained table,
+# so it can't drift the way a copied mapping would.
+host_targets_for_dir() {
+  local dir="$1"
+  grep -oE '^[[:space:]]*[A-Za-z0-9_-]+ = mkTarget \{[^}]*hostPath = \./hosts/'"${dir}"'/host\.nix;[^}]*\};' flake.nix \
+    | sed -E 's/^[[:space:]]*([A-Za-z0-9_-]+) = mkTarget.*/\1/' \
+    || true
+}
+
+declare -a changed_files=()
+scope_desc="full repo"
+
+if ! $full_check; then
+  resolve_base_ref() {
+    if [[ -n "${MAINT_BASE_SHA:-}" ]] && git cat-file -e "${MAINT_BASE_SHA}^{commit}" 2>/dev/null; then
+      echo "$MAINT_BASE_SHA"
+      return
+    fi
+    if git rev-parse --verify -q HEAD^ >/dev/null 2>&1; then
+      echo "HEAD^"
+      return
+    fi
+    git hash-object -t tree /dev/null
+  }
+
+  base_ref="$(resolve_base_ref)"
+  echo
+  echo "Changed-files scope: diffing against ${base_ref}"
+  mapfile -t changed_files < <(git diff --name-only --diff-filter=ACMR "$base_ref" -- . | sort -u)
+
+  if [[ ${#changed_files[@]} -eq 0 ]]; then
+    echo "No changed files detected."
+  else
+    printf '  %s\n' "${changed_files[@]}"
+  fi
+  scope_desc="changed files only (base: ${base_ref})"
+fi
+
+# Whole-tree fmt/lint always run under --full-check; otherwise scoped below.
+declare -a changed_nix_files=()
+for f in "${changed_files[@]:-}"; do
+  [[ "$f" == *.nix && -f "$f" ]] && changed_nix_files+=("$f")
+done
+
 echo
 echo "Checking Nix formatting with nixpkgs-fmt..."
-nix run --no-use-registries --no-accept-flake-config github:NixOS/nixpkgs/nixos-25.11#nixpkgs-fmt -- --check .
+if $full_check; then
+  nix run "${NIX_EVAL_FLAGS[@]}" github:NixOS/nixpkgs/nixos-25.11#nixpkgs-fmt -- --check .
+elif [[ ${#changed_nix_files[@]} -gt 0 ]]; then
+  nix run "${NIX_EVAL_FLAGS[@]}" github:NixOS/nixpkgs/nixos-25.11#nixpkgs-fmt -- --check "${changed_nix_files[@]}"
+else
+  echo "No changed .nix files; skipping."
+fi

 echo
 echo "Running statix lint..."
-nix run --no-use-registries --no-accept-flake-config github:NixOS/nixpkgs/nixos-25.11#statix -- check .
+if $full_check; then
+  nix run "${NIX_EVAL_FLAGS[@]}" github:NixOS/nixpkgs/nixos-25.11#statix -- check .
+elif [[ ${#changed_nix_files[@]} -gt 0 ]]; then
+  for f in "${changed_nix_files[@]}"; do
+    nix run "${NIX_EVAL_FLAGS[@]}" github:NixOS/nixpkgs/nixos-25.11#statix -- check "$f"
+  done
+else
+  echo "No changed .nix files; skipping."
+fi
+
+# Figure out which hosts/packages this run needs to eval (and, under
+# --dry-run, build). full_check always means "everything"; otherwise a
+# change to flake.nix/flake.lock/variables.nix/modules/common/* (repo-wide
+# inputs) or to any other modules/*.nix outside platforms//build-types
+# (whose blast radius isn't safely inferable from the path alone -- see
+# CLAUDE.md's "Grep modules/build-types/*.nix for each build type's imports
+# list") also falls back to everything, on the same reasoning CLAUDE.md
+# already gives interactive sessions for when to run the full sweep.
+# Anything more targeted -- a host.nix, a platform module, a build-type
+# module -- narrows to just the hosts it can affect.
+declare -A affected_hosts=()
+eval_packages=false
+
+if $full_check; then
+  for h in "${all_hosts[@]}"; do affected_hosts[$h]=1; done
+  eval_packages=true
+else
+  full_fallback=false
+  for f in "${changed_files[@]:-}"; do
+    case "$f" in
+      flake.nix|flake.lock|variables.nix|modules/common/*)
+        full_fallback=true
+        ;;
+    esac
+  done
+
+  if ! $full_fallback; then
+    for f in "${changed_files[@]:-}"; do
+      case "$f" in
+        hosts/*/*)
+          hostdir="${f#hosts/}"
+          hostdir="${hostdir%%/*}"
+          while IFS= read -r t; do
+            [[ -n "$t" ]] && affected_hosts[$t]=1
+          done < <(host_targets_for_dir "$hostdir")
+          ;;
+        modules/platforms/*.nix)
+          platform="$(basename "$f" .nix)"
+          for h in "${all_hosts[@]}"; do
+            [[ "$h" == "${platform}-"* ]] && affected_hosts[$h]=1
+          done
+          ;;
+        modules/build-types/*.nix)
+          buildtype="$(basename "$f" .nix)"
+          for h in "${all_hosts[@]}"; do
+            [[ "$h" == *"-${buildtype}" ]] && affected_hosts[$h]=1
+          done
+          ;;
+        modules/installer/*)
+          # iso.nix (imported by both the "installer" nixosConfigurations
+          # target and netbootSystem, which backs packages.pxe) pulls in
+          # common.nix, so a common.nix change reaches all three.
+          affected_hosts[installer]=1
+          eval_packages=true
+          ;;
+        modules/pxe-boot/*)
+          # stage-installer-artifacts.nix is imported by
+          # modules/build-types/pxe-boot.nix only -- same blast radius as a
+          # build-types/*.nix change, not a packages one.
+          for h in "${all_hosts[@]}"; do
+            [[ "$h" == *"-pxe-boot" ]] && affected_hosts[$h]=1
+          done
+          ;;
+        modules/*)
+          full_fallback=true
+          ;;
+      esac
+    done
+  fi
+
+  if $full_fallback; then
+    echo
+    echo "Changed files affect shared config; falling back to evaluating every host/package."
+    for h in "${all_hosts[@]}"; do affected_hosts[$h]=1; done
+    eval_packages=true
+  fi
+fi
+
+mapfile -t hosts < <(for h in "${!affected_hosts[@]}"; do echo "$h"; done | sort)

 echo
-echo "Evaluating host toplevel derivations..."
-for host in $hosts; do
-  echo "==> $host"
-  nix eval --raw --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath"
-done
+echo "Checking nix-cache host key for drift..."
+if bash "${script_dir}/secrets/sync-nix-cache-host-key.sh" --check; then
+  :
+else
+  drift_status=$?
+  if [[ "$drift_status" -eq 2 ]]; then
+    echo "nix-cache unreachable from here -- skipping host-key drift check."
+  else
+    echo "WARNING: nix-cache's host key has drifted from variables.nix (see above)." >&2
+    echo "  Run 'bash scripts/secrets/sync-nix-cache-host-key.sh' to fix." >&2
+  fi
+fi

-if [[ "$MODE" == "dry-run" ]]; then
-  echo
-  echo "Running dry-run builds for all hosts. This will not create result symlinks."
-  for host in $hosts; do
-    echo "==> Dry-run build: $host"
-    nix build --dry-run --no-link --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.toplevel"
+echo
+if [[ ${#hosts[@]} -eq 0 ]]; then
+  echo "No hosts affected by changed files; skipping host eval."
+else
+  echo "Evaluating host toplevel derivations (${scope_desc})..."
+  for host in "${hosts[@]}"; do
+    echo "==> $host"
+    nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath"
+
+    # lxc-* hosts deploy via a directly pct-restore-able tarball instead of
+    # nixos-install (see docs/auto-installer.md); proxmox-* hosts can
+    # alternatively be built as a standalone disk image (see
+    # docs/proxmox-images.md). Both are otherwise-unvalidated buildable
+    # surface, easy to silently break without this.
+    case "$host" in
+      lxc-*)
+        echo "==> $host (tarball)"
+        nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.tarball.drvPath"
+        ;;
+      proxmox-*)
+        echo "==> $host (diskoImagesScript)"
+        nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.diskoImagesScript.drvPath"
+        ;;
+    esac
  done
 fi

+echo
+if ! $eval_packages; then
+  echo "No packages affected by changed files; skipping package eval."
+else
+  echo "Evaluating buildable packages..."
+  for pkg in "${all_packages[@]}"; do
+    echo "==> packages.x86_64-linux.${pkg}"
+    nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#packages.x86_64-linux.${pkg}"
+  done
+fi
+
+if $dry_run; then
+  echo
+  echo "Running dry-run builds for the active scope. This will not create result symlinks."
+  for host in "${hosts[@]:-}"; do
+    echo "==> Dry-run build: $host"
+    nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.toplevel"
+
+    case "$host" in
+      lxc-*)
+        echo "==> Dry-run build: $host (tarball)"
+        nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.tarball"
+        ;;
+      proxmox-*)
+        echo "==> Dry-run build: $host (diskoImagesScript)"
+        nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.diskoImagesScript"
+        ;;
+    esac
+  done
+
+  if $eval_packages; then
+    echo
+    echo "Running dry-run builds for packages."
+    for pkg in "${all_packages[@]}"; do
+      echo "==> Dry-run build: packages.x86_64-linux.${pkg}"
+      nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#packages.x86_64-linux.${pkg}"
+    done
+  fi
+fi
+
 echo
 echo "Maintenance checks complete."
@@ -1,19 +1,11 @@
 #!/usr/bin/env bash
 set -euo pipefail

-export NIX_CONFIG="${NIX_CONFIG:-}
-experimental-features = nix-command flakes
-accept-flake-config = false
-warn-dirty = false
-"
-
-ensure_nix_profile() {
-  if [ -f /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh ]; then
-    . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
-  elif [ -f "$HOME/.nix-profile/etc/profile.d/nix.sh" ]; then
-    . "$HOME/.nix-profile/etc/profile.d/nix.sh"
-  fi
-}
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=lib/nix-bootstrap.sh
+source "${script_dir}/lib/nix-bootstrap.sh"
+# shellcheck source=lib/nix-eval.sh
+source "${script_dir}/lib/nix-eval.sh"

 install_nix_if_missing() {
  if command -v nix >/dev/null 2>&1; then
@@ -49,6 +41,17 @@ warn-dirty = false
 build-users-group = nixbld
 EOF

+    # The official installer's single-user root path still shells out to
+    # `sudo` to create /nix even though it already knows it's running as
+    # root -- confirmed live against a sudo-less minimal Debian/Proxmox
+    # node, where it fails with "sudo: not found" and prints this exact
+    # mkdir/chown as the manual fix. Pre-create it so that branch of the
+    # installer is skipped entirely.
+    if [ ! -d /nix ]; then
+      mkdir -m 0755 /nix
+      chown root /nix
+    fi
+
    sh <(curl -L https://nixos.org/nix/install) --no-daemon
  else
    sh <(curl -L https://nixos.org/nix/install) --no-daemon
@@ -79,13 +82,6 @@ if ! command -v jq >/dev/null 2>&1; then
 fi

 echo "Available NixOS hosts:"
-hosts="$(nix eval --json --no-use-registries --no-accept-flake-config .#nixosConfigurations --apply builtins.attrNames | jq -r '.[]')"
-echo "$hosts"
+list_flake_targets .

-echo "Evaluating all host toplevel derivations..."
-for host in $hosts; do
-  echo "==> Evaluating $host"
-  nix eval --raw --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath"
-done
-
-echo "Codex setup complete."
+echo "Codex setup complete. Run bash scripts/codex-maintenance.sh to validate changes."
@@ -1,9 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-#boot to rescue mode
-# set root password
-scp $RESULT_ISO root@$LINODE_IP:/tmp/nixos-auto.iso
-
-#in LISH or ssh to rescue mode
-dd if=/tmp/nixos.iso of=/dev/sda bs=4M status=progress conv=fsync
@@ -0,0 +1,174 @@
+#!/usr/bin/env bash
+# Shared config for scripts/*.sh. Source this instead of hardcoding a
+# second copy of these values in every script:
+#   source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/env.sh"
+# Every variable can still be overridden per-invocation via the
+# environment (e.g. PROXMOX_STORAGE=tank-nvme ./scripts/proxmox/create-proxmox-resource.sh ...)
+# since each one only sets a default if unset.
+
+# Two SSH-reachable Proxmox nodes exist on the LAN:
+#   - pve1.sweet.home      -- production. Real, live VMs/containers.
+#   - pve-test.sweet.home  -- sandbox/test node, for scratch VMs/containers
+#     that don't belong on production.
+#
+# PROXMOX_HOST is what scripts/proxmox/create-proxmox-resource.sh actually
+# targets by default -- overridable per-invocation with --node <hostname>,
+# or per-variable as usual (e.g. PROXMOX_HOST=$PVE_TEST_HOST). It defaults
+# to production, matching this repo's behavior before pve-test existed --
+# see CLAUDE.md's "Two Proxmox nodes" section for the policy on which
+# situations should target which node (in particular: Claude defaults to
+# pve-test, not this variable's own default, unless explicitly told
+# otherwise).
+: "${PVE1_HOST:=pve1.sweet.home}"
+: "${PVE_TEST_HOST:=pve-test.sweet.home}"
+: "${PROXMOX_HOST:=$PVE1_HOST}"
+: "${PROXMOX_SSH_USER:=root}"
+
+# Where this flake repo lives on the Proxmox node itself.
+# scripts/proxmox/create-proxmox-resource.sh builds images directly on the node
+# instead of transferring them over the network -- it clones the repo here
+# (from this checkout's own `origin` remote) the first time it doesn't
+# find it, installing build tooling via scripts/codex-setup.sh, then
+# `git pull`s it before every subsequent build.
+: "${PROXMOX_REMOTE_REPO_DIR:=/root/nixos}"
+
+# Storage pool names -- Proxmox's own stock-install defaults, but this
+# varies a lot by setup (ZFS pool name, custom LVM-thin volume, etc.).
+# Verify with `pvesm status` on the node and correct these if wrong.
+: "${PROXMOX_STORAGE:=local-zfs}"     # VM disks / CT rootfs
+: "${PROXMOX_ISO_STORAGE:=local}"     # uploaded images/ISOs/CT templates
+
+: "${PROXMOX_BRIDGE:=vmbr0}"
+
+# Fallback resource sizing when a script doesn't get --cores/--memory.
+: "${PROXMOX_DEFAULT_CORES:=2}"
+: "${PROXMOX_DEFAULT_MEMORY_MB:=2048}"
+
+# `pct create` (unlike `pct restore`) requires an explicit rootfs size --
+# no backup metadata to infer it from. Matches Proxmox's own GUI default.
+: "${PROXMOX_DEFAULT_LXC_DISK_GB:=8}"
+
+# `pct create --memory` only sets RAM -- swap is a wholly separate
+# parameter that otherwise silently stays at Proxmox's own 512M default
+# regardless of --memory (confirmed: creating with --memory 2048 left
+# swap at 512). create-proxmox-resource.sh defaults --swap to whatever
+# --memory resolves to at runtime rather than a static value here, so it
+# tracks a --memory picked at the CLI too, not just the default above.
+
+# Required for a modern (v247+) systemd guest to actually boot as an
+# unprivileged container: systemd's routine use of nested user namespaces
+# and credential mounts (LoadCredential=, DynamicUser=, etc. -- used even
+# by plain getty units) gets denied by AppArmor's default LXC confinement
+# without these. Confirmed live: without them, every getty unit
+# crash-loops on a denied `/run/credentials/*` mount every ~3s (visible
+# as garbage on the console) and core services like nsncd fail the same
+# way on userns_create; system.build.tarball never finishes activating.
+#
+# mount=nfs;nfs4: without it, AppArmor blanket-denies the `nfs`/
+# `rpc_pipefs` mount syscalls any NFS client share needs -- confirmed
+# live on lxc-docker (which mounts several, see modules/docker/mount-data.nix
+# and modules/raspi/mount-data.nix): `mount: /var/lib/nfs/rpc_pipefs:
+# permission denied`. Harmless to grant on lxc targets that don't mount
+# NFS at all -- it only widens what the container is *allowed* to mount,
+# nothing here forces a mount to happen.
+: "${PROXMOX_DEFAULT_LXC_FEATURES:=nesting=1,keyctl=1,mount=nfs;nfs4}"
+
+export PVE1_HOST PVE_TEST_HOST PROXMOX_HOST PROXMOX_SSH_USER PROXMOX_STORAGE \
+  PROXMOX_ISO_STORAGE PROXMOX_BRIDGE PROXMOX_DEFAULT_CORES \
+  PROXMOX_DEFAULT_MEMORY_MB PROXMOX_DEFAULT_LXC_DISK_GB \
+  PROXMOX_DEFAULT_LXC_FEATURES PROXMOX_REMOTE_REPO_DIR
+
+# Matches variables.nix's nixCacheHost -- update both if it ever changes.
+: "${NIX_CACHE_HOST:=nix-cache}"
+export NIX_CACHE_HOST
+
+# nix_extra_opts: call as a plain statement (NOT inside $(...)/<(...) --
+# that forks a subshell, and the whole point is exporting a decision back
+# into *this* shell) to populate the global NIX_OPTS array with whatever
+# extra `nix`/`nix-shell` CLI options are needed to avoid nix-cache when
+# it's unreachable:
+#   nix_extra_opts
+#   nix build "${NIX_OPTS[@]}" ...
+#
+# Without this, every single `nix eval`/`nix build` call retries each
+# store path against a dead substituter up to 5 times with backoff
+# (confirmed: ~15s+ per lookup even with a short connect-timeout, because
+# nix's own retry count isn't controllable that way), and separately
+# tries it as a remote builder too -- both fail independently, so both
+# are checked.
+#
+# Checked with a single fast `curl`/TCP probe (bypassing nix's retry logic
+# entirely) the first time this is called in a given process, and the
+# result is exported as NIX_EXTRA_OPTS so a script that shells out to
+# another script in this repo (e.g. create-proxmox-resource.sh calling
+# sync-host-keys.sh) reuses the same decision instead of probing twice.
+declare -a NIX_OPTS=()
+
+nix_extra_opts() {
+  if [[ -n "${NIX_EXTRA_OPTS_DECIDED:-}" ]]; then
+    if [[ -n "${NIX_EXTRA_OPTS:-}" ]]; then
+      eval "NIX_OPTS=(${NIX_EXTRA_OPTS})"
+    else
+      NIX_OPTS=()
+    fi
+    return
+  fi
+  export NIX_EXTRA_OPTS_DECIDED=1
+  NIX_OPTS=()
+
+  # Retry a couple of times, 1s apart, before believing either check --
+  # belt-and-suspenders against a genuine multi-second blip (nix-cache
+  # restarting), on top of the fix below. Worst case (~11s total, host
+  # genuinely gone) is still nowhere near the 15s+ *per lookup* nix's own
+  # substituter retries would cost if this check didn't exist at all.
+  local attempt cache_up=0 builder_up=0
+  for attempt in 1 2 3; do
+    if curl --silent --fail --max-time 3 "http://${NIX_CACHE_HOST}/nix-cache-info" >/dev/null 2>&1; then
+      cache_up=1
+      break
+    fi
+    [[ "$attempt" -lt 3 ]] && sleep 1
+  done
+
+  if [[ "$cache_up" -eq 0 ]]; then
+    echo "nix-cache (http://${NIX_CACHE_HOST}) is unreachable -- skipping it (substituter + remote builder) for the rest of this run." >&2
+    NIX_OPTS=(--option substituters "https://cache.nixos.org/" --builders "")
+  else
+    for attempt in 1 2 3; do
+      # `exec 3<>/dev/tcp/...` just opens the fd and returns -- it does NOT
+      # read from it. Confirmed live this is load-bearing, not stylistic:
+      # the previous `cat < /dev/tcp/.../22` blocked forever and always hit
+      # the timeout even against a perfectly healthy nix-cache, because
+      # sshd sends its banner and then holds the connection open waiting
+      # for the client to speak next -- `cat` never sees EOF, so this
+      # check reported "unreachable" unconditionally, 100% of the time,
+      # regardless of whether the remote builder was actually up.
+      if timeout 3 bash -c "exec 3<>/dev/tcp/${NIX_CACHE_HOST}/22" 2>/dev/null; then
+        builder_up=1
+        break
+      fi
+      [[ "$attempt" -lt 3 ]] && sleep 1
+    done
+    if [[ "$builder_up" -eq 0 ]]; then
+      echo "nix-cache's SSH remote builder (nixremote@${NIX_CACHE_HOST}:22) is unreachable -- disabling remote builds for the rest of this run." >&2
+      NIX_OPTS=(--builders "")
+    fi
+  fi
+
+  # `printf '%q '` with a genuinely empty NIX_OPTS still runs one format
+  # pass over a missing argument and yields the literal `'' ` rather than
+  # an empty string (confirmed live) -- a subprocess that later does
+  # `eval "NIX_OPTS=(${NIX_EXTRA_OPTS})"` (the branch above, for e.g.
+  # sync-host-keys.sh reusing this process's decision) would then rebuild
+  # a 1-element array holding an empty string instead of a 0-element
+  # array, and `nix-shell "${NIX_OPTS[@]}" -p <pkg>` chokes on that stray
+  # element as a bogus positional argument. Guard the empty case
+  # explicitly so nix-cache being reachable (NIX_OPTS legitimately empty)
+  # round-trips as truly empty instead.
+  if [[ ${#NIX_OPTS[@]} -gt 0 ]]; then
+    printf -v NIX_EXTRA_OPTS '%q ' "${NIX_OPTS[@]}"
+  else
+    NIX_EXTRA_OPTS=""
+  fi
+  export NIX_EXTRA_OPTS
+}
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Shared "type X to confirm" prompt for scripts/proxmox/create-proxmox-resource.sh
+# (--modify, and replacing an existing --allow-duplicate-host resource) and
+# scripts/secrets/sync-host-keys.sh (--regenerate-all-keys) -- three destructive
+# confirmations that all work the same way (echo the expected value back
+# exactly), kept in one place so the prompt/comparison logic can't drift.
+# Source alongside env.sh:
+#   source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/lib/confirm.sh"
+#
+# Deliberately does NOT print anything on mismatch or decide exit-vs-return
+# -- callers vary on both (a top-level script exits, a subcommand function
+# returns; wording differs too), so that stays at the call site.
+
+# confirm_typed <expected> <prompt>
+# Prints <prompt> via `read -rp`, then reports (via exit status) whether the
+# typed input matched <expected> exactly.
+confirm_typed() {
+  local expected="$1" prompt="$2" input
+  read -rp "$prompt" input
+  [[ "$input" == "$expected" ]]
+}
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Shared Nix bootstrap for scripts/codex-setup.sh and
+# scripts/codex-maintenance.sh: the nix.conf settings both need in effect
+# before a single `nix` command runs (flakes enabled, never honor a flake
+# input's own nixConfig, no "dirty tree" warning spam), plus a helper to
+# pull an already-installed Nix's daemon/profile script onto PATH if it
+# isn't there yet. Source this instead of copying it -- see CLAUDE.md.
+export NIX_CONFIG="${NIX_CONFIG:-}
+experimental-features = nix-command flakes
+accept-flake-config = false
+warn-dirty = false
+"
+
+ensure_nix_profile() {
+  if [ -f /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh ]; then
+    . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
+  elif [ -f "$HOME/.nix-profile/etc/profile.d/nix.sh" ]; then
+    . "$HOME/.nix-profile/etc/profile.d/nix.sh"
+  fi
+}
@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+# Shared flake-introspection helpers for scripts/*.sh. Source alongside
+# env.sh:
+#   source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/lib/nix-eval.sh"
+#
+# NIX_EVAL_FLAGS: --no-use-registries so a call here never resolves through
+# the user's global flake registry (every call targets this repo's own
+# flake, or an explicit github: ref, not a registry alias); --no-accept-flake-config
+# so a flake input's own nixConfig (e.g. a dependency's substituters) is
+# never honored -- matches accept-flake-config = false already set repo-wide
+# (see lib/nix-bootstrap.sh / CLAUDE.md). Reuse this array rather than
+# retyping the two flags at each call site.
+declare -a NIX_EVAL_FLAGS=(--no-use-registries --no-accept-flake-config)
+
+# list_flake_targets <flake_ref>
+# Prints the attribute names under <flake_ref>#nixosConfigurations, one per
+# line, e.g.:
+#   list_flake_targets .            # from inside the repo
+#   list_flake_targets "$repo_root" # from anywhere
+list_flake_targets() {
+  local flake_ref="$1"
+  nix eval --json "${NIX_EVAL_FLAGS[@]}" \
+    "${flake_ref}#nixosConfigurations" --apply builtins.attrNames \
+  | jq -r '.[]'
+}
+
+# flake_target_hostname <flake_ref> <target>
+# Prints one nixosConfigurations target's config.networking.hostName.
+# Empty (not an error under set -e) if the target doesn't exist or the
+# eval otherwise fails -- callers that need to distinguish "empty" from
+# "eval failed" should check $? themselves instead of relying on this.
+flake_target_hostname() {
+  local flake_ref="$1" target="$2"
+  nix eval --raw "${NIX_EVAL_FLAGS[@]}" \
+    "${flake_ref}#nixosConfigurations.${target}.config.networking.hostName" 2>/dev/null
+}
+
+# flake_target_lxc_privileged <flake_ref> <target>
+# Prints "true" or "false" for one lxc-* target's config.proxmoxLXC.privileged
+# (modules/platforms/lxc.nix is the single source of truth -- e.g.
+# lxc-docker sets this true so it can NFS-mount; every other lxc-* host
+# stays unprivileged). Only meaningful for lxc-* targets -- the option
+# doesn't exist for linode-*/proxmox-* (nixpkgs' proxmox-lxc.nix, which
+# declares it, is only ever imported by modules/platforms/lxc.nix). Empty
+# (not an error under set -e) if the eval fails.
+flake_target_lxc_privileged() {
+  local flake_ref="$1" target="$2"
+  # Not --raw: the option is a Nix boolean, and --raw can only coerce
+  # strings ("cannot coerce a Boolean to a string"). Plain `nix eval`
+  # prints a bare `true`/`false` for a boolean, which is exactly the
+  # string this needs.
+  nix eval "${NIX_EVAL_FLAGS[@]}" \
+    "${flake_ref}#nixosConfigurations.${target}.config.proxmoxLXC.privileged" 2>/dev/null
+}
@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+# Shared sops/age helpers for scripts/secrets/backup-admin-key.sh,
+# scripts/secrets/rotate-admin-key.sh, and scripts/secrets/sync-host-keys.sh -- all three
+# derive an age public key from a private identity file the same way, two
+# of them resolve the same sops/age default key-file path, and two of them
+# run `sops updatekeys` the same way. Kept in one place so they can't drift
+# apart. Source alongside env.sh:
+#   source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/lib/sops-age.sh"
+#
+# Uses NIX_OPTS (an array of extra `nix-shell` options -- see env.sh's
+# nix_extra_opts) if the caller has already set it, same convention as
+# lib/ssh-host-keys.sh. Falls back to no extra options if the caller never
+# sourced env.sh.
+if ! declare -p NIX_OPTS >/dev/null 2>&1; then
+  declare -a NIX_OPTS=()
+fi
+
+# sops/age's own default identity-file resolution order, minus $SOPS_AGE_KEY
+# itself (an inline identity, not a path -- callers that accept it check it
+# separately, before falling back to this).
+: "${DEFAULT_SOPS_AGE_KEY_FILE:=${SOPS_AGE_KEY_FILE:-${XDG_CONFIG_HOME:-$HOME/.config}/sops/age/keys.txt}}"
+
+# age_pubkey_from_identity_file <identity-file>
+# Prints the age public key for a private identity file (age-keygen -y).
+age_pubkey_from_identity_file() {
+  local identity_file="$1"
+  nix-shell "${NIX_OPTS[@]}" -p age --run "age-keygen -y '${identity_file}'"
+}
+
+# sops_yaml_admin_pubkey <sops-yaml-path>
+# Prints .sops.yaml's current &admin age public key, or empty (not an error
+# under set -e) if no such anchor line exists -- callers that need to treat
+# "missing" as fatal check for an empty result themselves.
+sops_yaml_admin_pubkey() {
+  local sops_yaml="$1"
+  grep -E '^  - &admin age1' "$sops_yaml" 2>/dev/null | awk '{print $NF}' || true
+}
+
+# sops_updatekeys <secrets-file> [key-file]
+# Re-encrypts <secrets-file> for .sops.yaml's current recipient set. If
+# <key-file> is given, decrypts with that identity (SOPS_AGE_KEY_FILE)
+# instead of whatever's ambient -- needed when the ambient default key
+# doesn't match yet (e.g. mid-rotation, decrypting with the outgoing key).
+sops_updatekeys() {
+  local secrets_file="$1" key_file="${2:-}"
+  if [[ -n "$key_file" ]]; then
+    SOPS_AGE_KEY_FILE="$key_file" nix-shell "${NIX_OPTS[@]}" -p sops --run \
+      "sops updatekeys --yes '${secrets_file}'"
+  else
+    nix-shell "${NIX_OPTS[@]}" -p sops --run "sops updatekeys --yes '${secrets_file}'"
+  fi
+}
@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# Shared SSH-host-key / age-conversion helpers for scripts/secrets/sync-host-keys.sh
+# and scripts/secrets/prepare-host-key.sh -- both generate the same kind of key
+# (ed25519, no passphrase, the sops-nix age-derivation input) and convert it
+# to an age recipient the same way; kept in one place so the two can't
+# drift apart.
+#
+# Uses NIX_OPTS (an array of extra `nix-shell` options -- see env.sh's
+# nix_extra_opts) if the caller has already set it, so a decision to avoid
+# an unreachable nix-cache is reused here instead of probed again. Falls
+# back to no extra options if the caller never sourced env.sh.
+if ! declare -p NIX_OPTS >/dev/null 2>&1; then
+  declare -a NIX_OPTS=()
+fi
+
+# generate_host_ed25519_key <hostname> <keyfile>
+# Writes <keyfile> and <keyfile>.pub. Caller is responsible for refusing to
+# overwrite an existing keyfile -- this always runs ssh-keygen fresh.
+generate_host_ed25519_key() {
+  local hostname="$1" keyfile="$2"
+  nix-shell "${NIX_OPTS[@]}" -p openssh --run \
+    "ssh-keygen -t ed25519 -N '' -C '${hostname}' -f '${keyfile}'" >/dev/null
+}
+
+# ssh_pubkey_to_age <pubkeyfile>
+# Prints the age public key derived from an ed25519 SSH public key file.
+ssh_pubkey_to_age() {
+  local pubkeyfile="$1"
+  nix-shell "${NIX_OPTS[@]}" -p ssh-to-age --run "ssh-to-age -i '${pubkeyfile}'"
+}
@@ -0,0 +1,180 @@
+#!/usr/bin/env python3
+# Companion to scripts/sync-host-keys.sh. Applies a set of additive edits
+# to .sops.yaml via targeted line insertion -- not a full YAML parse and
+# re-serialize -- so every untouched byte of the file is guaranteed to stay
+# exactly as it was (a full round-trip through a generic YAML library was
+# tested and silently reformatted the whole file's indentation style).
+#
+# Reads a JSON edit plan from stdin:
+#   {
+#     "add_keys": [{"host": "lxc-server", "age_key": "age1..."}],
+#     "add_aliases": [{"host": "lxc-server", "basename": "common.yaml"}],
+#     "remove_keys": ["lxc-server"],
+#     "remove_aliases_for_hosts": ["lxc-server"]
+#   }
+# Idempotent: an anchor or alias that's already present/absent is left
+# alone -- adding what's already there, or removing what's already gone,
+# is a no-op rather than an error.
+# Prints a JSON summary of what actually changed to stdout, so the caller
+# knows which secrets/*.yaml files need `sops updatekeys` and which don't.
+import json
+import re
+import sys
+
+KEY_LINE_RE = re.compile(r"^  - &\S+ age1")
+
+
+def add_keys(lines, add_keys):
+    existing_anchors = set()
+    for line in lines:
+        m = re.match(r"^  - &(\S+) age1", line)
+        if m:
+            existing_anchors.add(m.group(1))
+
+    new = [e for e in add_keys if e["host"] not in existing_anchors]
+    if not new:
+        return lines, []
+
+    last_idx = None
+    for i, line in enumerate(lines):
+        if KEY_LINE_RE.match(line):
+            last_idx = i
+    if last_idx is None:
+        print("ERROR: no '  - &<name> age1...' line found under keys: in .sops.yaml", file=sys.stderr)
+        sys.exit(1)
+
+    insert = [f"  - &{e['host']} {e['age_key']}\n" for e in new]
+    lines = lines[: last_idx + 1] + insert + lines[last_idx + 1 :]
+    return lines, [e["host"] for e in new]
+
+
+def add_aliases(lines, add_aliases):
+    changed_files = []
+    for e in add_aliases:
+        host = e["host"]
+        basename = e["basename"]
+        target = "path_regex: secrets/" + basename.replace(".", r"\.") + "$"
+
+        rule_start = None
+        for i, line in enumerate(lines):
+            if target in line:
+                rule_start = i
+                break
+        if rule_start is None:
+            print(
+                f"WARNING: no creation_rule for secrets/{basename} in .sops.yaml "
+                f"(needed by {host}) -- add one manually, then re-run.",
+                file=sys.stderr,
+            )
+            continue
+
+        rule_end = len(lines)
+        for i in range(rule_start + 1, len(lines)):
+            if re.match(r"^  - path_regex:", lines[i]):
+                rule_end = i
+                break
+
+        block = lines[rule_start:rule_end]
+        if any(re.search(r"\*" + re.escape(host) + r"\s*$", line) for line in block):
+            continue  # already present
+
+        last_alias_idx = None
+        last_alias_indent = None
+        for i in range(rule_start, rule_end):
+            m = re.match(r"^(\s*)- \*\S+\s*$", lines[i])
+            if m:
+                last_alias_idx = i
+                last_alias_indent = m.group(1)
+        if last_alias_idx is None:
+            print(
+                f"WARNING: creation_rule for secrets/{basename} has no existing "
+                f"'- *alias' line to anchor the insertion point -- add {host} manually.",
+                file=sys.stderr,
+            )
+            continue
+
+        new_line = f"{last_alias_indent}- *{host}\n"
+        lines = lines[: last_alias_idx + 1] + [new_line] + lines[last_alias_idx + 1 :]
+        changed_files.append(basename)
+    return lines, changed_files
+
+
+def remove_keys(lines, hosts):
+    hosts = set(hosts)
+    removed = []
+    kept = []
+    for line in lines:
+        m = re.match(r"^  - &(\S+) age1", line)
+        if m and m.group(1) in hosts:
+            removed.append(m.group(1))
+            continue
+        kept.append(line)
+    return kept, removed
+
+
+def remove_aliases_for_hosts(lines, hosts):
+    hosts = set(hosts)
+    if not hosts:
+        return lines, []
+
+    changed_files = []
+    result = []
+    current_basename = None
+    current_block_changed = False
+
+    def flush():
+        if current_block_changed and current_basename:
+            changed_files.append(current_basename)
+
+    for line in lines:
+        if re.match(r"^  - path_regex:", line):
+            flush()
+            current_block_changed = False
+            m = re.search(r"path_regex: secrets/(.+)\$", line)
+            current_basename = m.group(1).replace(r"\.", ".") if m else None
+            result.append(line)
+            continue
+
+        if current_basename is not None and any(
+            re.search(r"\*" + re.escape(h) + r"\s*$", line) for h in hosts
+        ):
+            current_block_changed = True
+            continue  # drop this alias line
+
+        result.append(line)
+
+    flush()
+    return result, changed_files
+
+
+def main():
+    sops_path = sys.argv[1]
+    edits = json.load(sys.stdin)
+
+    with open(sops_path) as f:
+        lines = f.readlines()
+
+    lines, added_keys = add_keys(lines, edits.get("add_keys", []))
+    lines, added_alias_files = add_aliases(lines, edits.get("add_aliases", []))
+    lines, removed_keys = remove_keys(lines, edits.get("remove_keys", []))
+    lines, removed_alias_files = remove_aliases_for_hosts(
+        lines, edits.get("remove_aliases_for_hosts", [])
+    )
+
+    with open(sops_path, "w") as f:
+        f.writelines(lines)
+
+    changed_files = sorted(set(added_alias_files) | set(removed_alias_files))
+    json.dump(
+        {
+            "added_keys": added_keys,
+            "removed_keys": removed_keys,
+            "changed_secrets_files": changed_files,
+        },
+        sys.stdout,
+    )
+    print()
+
+
+if __name__ == "__main__":
+    main()
@@ -0,0 +1,221 @@
+#!/usr/bin/env bash
+# Ad hoc clone of a single VM/CT from pve1 (production) to pve-test
+# (sandbox), via vzdump + qmrestore/pct restore -- not a general-purpose
+# backup tool, just a quick "give me a disposable copy of this thing on
+# pve-test" for testing against real-ish data without touching prod.
+#
+# Flow:
+#   1. vzdump the resource on pve1 into its "local" storage (--mode
+#      snapshot by default, so the source keeps running throughout --
+#      see --mode below for when that's not possible).
+#   2. Stream the resulting archive straight from pve1 to pve-test
+#      (ssh pve1 cat ... | ssh pve-test cat > ...) -- this machine is
+#      just the relay, no separate on-disk staging copy here.
+#   3. qmrestore / pct restore it on pve-test under --new-vmid (default:
+#      same VMID as the source -- pve-test is a separate node/cluster, so
+#      no collision unless that VMID is already in use there too).
+#      Always restored with --unique 1 (fresh MAC addresses) since the
+#      source is typically still running on the same LAN -- restoring
+#      with the *same* MAC would put two live guests on the wire with
+#      identical hardware addresses.
+#   4. Delete the vzdump archive from pve1's local storage and the
+#      relayed copy on pve-test, so neither node accumulates ad hoc
+#      backup files from this script. Only the pve1 original is
+#      preserved on any failure after step 1, so a failed
+#      transfer/restore can be retried without re-running the backup.
+#
+# This script's own defaults are pve1 -> pve-test, unlike
+# create-proxmox-resource.sh's --node (which defaults to production) --
+# see CLAUDE.md's "Two Proxmox nodes" section. pve1 is only ever touched
+# here after typing the source VMID back to confirm; pve-test is treated
+# as disposable, matching this repo's usual policy for that node.
+#
+# See --help for the full option list.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=../lib/confirm.sh
+source "${repo_root}/scripts/lib/confirm.sh"
+
+usage() {
+  cat <<EOF
+Usage: $0 --vmid <n> [options]
+
+  --vmid <n>              Required: VMID on the source node to clone.
+                           Kind (qemu VM vs LXC CT) is auto-detected.
+  --new-vmid <n>           VMID to restore as on the target node
+                           (default: same as --vmid).
+  --mode snapshot|suspend|stop
+                           vzdump backup mode (default: snapshot -- the
+                           source resource keeps running throughout;
+                           requires snapshot-capable storage, e.g.
+                           ZFS/LVM-thin/Ceph/qcow2). Fall back to
+                           "suspend" (brief pause) or "stop" (source
+                           goes down for the duration) if the source's
+                           storage doesn't support live snapshots --
+                           vzdump's own error will say so.
+  --source-node <host>      (default: \$PVE1_HOST, ${PVE1_HOST})
+  --target-node <host>       (default: \$PVE_TEST_HOST, ${PVE_TEST_HOST})
+  --source-storage <pool>      Where vzdump writes the backup on the
+                               source node (default: local).
+  --target-storage <pool>       Where the restored disk/rootfs lands on
+                               the target node (default: \$PROXMOX_STORAGE, ${PROXMOX_STORAGE}).
+  --keep-backup                  Don't delete the vzdump archive from
+                                 either node afterward (debugging aid).
+  --yes                            Skip the typed VMID confirmation
+                                   before touching the source node.
+  --dry-run                          Print the full plan and skip every
+                                     mutating step (vzdump, transfer,
+                                     restore, delete) and the confirm
+                                     prompt. Still makes read-only SSH
+                                     calls to look up the source kind
+                                     and check the target VMID is free
+                                     -- harmless on either node.
+  -h, --help
+EOF
+}
+
+vmid=""
+new_vmid=""
+mode="snapshot"
+source_node="$PVE1_HOST"
+target_node="$PVE_TEST_HOST"
+source_storage="local"
+target_storage="$PROXMOX_STORAGE"
+keep_backup=0
+skip_confirm=0
+dry_run=0
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+  --vmid) vmid="$2"; shift 2 ;;
+  --new-vmid) new_vmid="$2"; shift 2 ;;
+  --mode) mode="$2"; shift 2 ;;
+  --source-node) source_node="$2"; shift 2 ;;
+  --target-node) target_node="$2"; shift 2 ;;
+  --source-storage) source_storage="$2"; shift 2 ;;
+  --target-storage) target_storage="$2"; shift 2 ;;
+  --keep-backup) keep_backup=1; shift ;;
+  --yes) skip_confirm=1; shift ;;
+  --dry-run) dry_run=1; shift ;;
+  -h | --help) usage; exit 0 ;;
+  *) echo "Unknown option: $1" >&2; usage >&2; exit 1 ;;
+  esac
+done
+
+if [[ -z "$vmid" ]]; then
+  echo "ERROR: --vmid is required." >&2
+  usage >&2
+  exit 1
+fi
+if [[ "$mode" != "snapshot" && "$mode" != "suspend" && "$mode" != "stop" ]]; then
+  echo "ERROR: --mode must be snapshot, suspend, or stop." >&2
+  exit 1
+fi
+[[ -z "$new_vmid" ]] && new_vmid="$vmid"
+
+source_target="${PROXMOX_SSH_USER}@${source_node}"
+target_target="${PROXMOX_SSH_USER}@${target_node}"
+
+# No dry-run wrapper needed for the calls below: every mutating step
+# (vzdump, transfer, restore, delete) is reached only after the --dry-run
+# early-exit further down, so a plain `ssh` call is never in the dry-run
+# path.
+
+# --- identify the resource kind on the source node -----------------------
+echo "==> Looking up VMID ${vmid} on ${source_node}..."
+kind=""
+if ssh "$source_target" "qm status ${vmid}" >/dev/null 2>&1; then
+  kind="vm"
+elif ssh "$source_target" "pct status ${vmid}" >/dev/null 2>&1; then
+  kind="lxc"
+else
+  echo "ERROR: VMID ${vmid} doesn't exist on ${source_node} as either a VM or CT." >&2
+  exit 1
+fi
+echo "VMID ${vmid} on ${source_node} is a ${kind}."
+
+# --- refuse to clobber an existing resource on the target node -----------
+if ssh "$target_target" "qm status ${new_vmid}" >/dev/null 2>&1 \
+  || ssh "$target_target" "pct status ${new_vmid}" >/dev/null 2>&1; then
+  echo "ERROR: VMID ${new_vmid} already exists on ${target_node}. Pass --new-vmid" >&2
+  echo "with a free ID, or remove the existing resource there first." >&2
+  exit 1
+fi
+
+echo
+echo "Plan:"
+echo "  source: ${kind} VMID ${vmid} on ${source_node} (storage: ${source_storage}, mode: ${mode})"
+echo "  target: VMID ${new_vmid} on ${target_node} (storage: ${target_storage}, fresh MAC via --unique)"
+[[ "$keep_backup" -eq 1 ]] && echo "  backup archives are kept on both nodes afterward (--keep-backup)"
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] No backup, transfer, restore, or delete was performed."
+  exit 0
+fi
+
+if [[ "$skip_confirm" -ne 1 ]]; then
+  echo
+  if ! confirm_typed "$vmid" "Type the source VMID (${vmid}) to confirm backing it up from ${source_node}: "; then
+    echo "Cancelled -- input didn't match ${vmid}." >&2
+    exit 1
+  fi
+fi
+
+# --- vzdump on the source node --------------------------------------------
+echo
+echo "==> Backing up VMID ${vmid} on ${source_node} (mode=${mode}, storage=${source_storage})..."
+vzdump_log="$(ssh "$source_target" \
+  "vzdump ${vmid} --mode ${mode} --storage ${source_storage} --compress zstd" 2>&1)" \
+  || {
+    echo "$vzdump_log" >&2
+    echo "ERROR: vzdump failed on ${source_node}." >&2
+    exit 1
+  }
+echo "$vzdump_log"
+
+archive="$(echo "$vzdump_log" | grep -oP "creating vzdump archive '\K[^']+" | tail -n1)"
+if [[ -z "$archive" ]]; then
+  echo "ERROR: couldn't find the archive path in vzdump's output above." >&2
+  exit 1
+fi
+archive_basename="$(basename "$archive")"
+target_tmp_archive="/var/tmp/${archive_basename}"
+echo "Archive: ${archive}"
+
+# Always clean up the relayed copy on the target node, success or failure
+# -- it's only ever a working copy, restored or not.
+cleanup_target_tmp() {
+  if [[ "$keep_backup" -ne 1 ]]; then
+    ssh "$target_target" "rm -f '${target_tmp_archive}'" >/dev/null 2>&1 || true
+  fi
+}
+trap cleanup_target_tmp EXIT
+
+# --- relay the archive from source to target ------------------------------
+echo
+echo "==> Transferring archive to ${target_node}..."
+ssh "$source_target" "cat '${archive}'" | ssh "$target_target" "cat > '${target_tmp_archive}'"
+
+# --- restore on the target node --------------------------------------------
+echo
+echo "==> Restoring as VMID ${new_vmid} on ${target_node} (storage=${target_storage})..."
+if [[ "$kind" == "vm" ]]; then
+  ssh "$target_target" "qmrestore '${target_tmp_archive}' ${new_vmid} --storage ${target_storage} --unique 1"
+else
+  ssh "$target_target" "pct restore ${new_vmid} '${target_tmp_archive}' --storage ${target_storage} --unique 1"
+fi
+
+# --- clean up the source backup now that the restore succeeded -----------
+if [[ "$keep_backup" -ne 1 ]]; then
+  echo
+  echo "==> Deleting backup archive from ${source_node}'s ${source_storage} storage..."
+  ssh "$source_target" "rm -f '${archive}' '${archive}.notes' '${archive}.log'" >/dev/null 2>&1 || true
+fi
+
+echo
+echo "Done. VMID ${new_vmid} (${kind}) is now on ${target_node}, cloned from" \
+  "VMID ${vmid} on ${source_node}."
@@ -0,0 +1,182 @@
+#!/usr/bin/env bash
+# Points a non-NixOS Debian machine's Nix install at nix-cache: adds it as
+# a substituter (with cache.nixos.org kept as fallback) and, once the
+# remote-builder private key is installed, as a distributed-build machine
+# too.
+#
+# This is the non-NixOS equivalent of modules/nix-cache/client.nix +
+# modules/nix-cache/remote-builder-client.nix -- those two only apply to
+# hosts built from this flake. A plain Debian box with Nix installed
+# (single- or multi-user install, nix-daemon running) has no NixOS module
+# system to pick that config up, so this edits /etc/nix/nix.conf by hand
+# instead. Run this ON the target Debian machine, as root.
+#
+# The values below mirror variables.nix / modules/nix-cache/client.nix in
+# this repo -- update both if nix-cache is ever rebuilt with a new host
+# key or the cache signing key is rotated (see docs/nix-cache.md).
+#
+# REMOTE_BUILDER_KEY defaults to this machine's own default root SSH
+# identity (matches modules/nix-cache/remote-builder-client.nix's
+# convention for real NixOS clients: authenticate as nixremote with the
+# host's own default key, added individually to
+# vars.remoteBuilderAuthorizedKeys, rather than a separately-named or
+# shared keypair) -- generate one with
+# `ssh-keygen -t ed25519 -N '' -f /root/.ssh/id_ed25519` if this machine
+# doesn't have one yet, then add its .pub to vars.remoteBuilderAuthorizedKeys
+# and rebuild nix-cache.
+#
+# Usage:
+#   sudo ./configure-nix-cache-client.sh [--dry-run] [--no-remote-builder] [--no-restart]
+#
+# Env overrides (defaults match variables.nix):
+#   NIX_CACHE_HOST, NIX_CACHE_HOST_KEY, REMOTE_BUILDER_USER, REMOTE_BUILDER_KEY
+
+set -euo pipefail
+
+: "${NIX_CACHE_HOST:=nix-cache}"
+: "${NIX_CACHE_HOST_KEY:=ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPeWgMsdaiz4axT/deFc1+0B5bN+GX/NOeW9bbQ0c/IT lxc-nix-cache}"
+: "${REMOTE_BUILDER_USER:=nixremote}"
+: "${REMOTE_BUILDER_KEY:=/root/.ssh/id_ed25519}"
+
+CACHE_PUB_KEY="cache.local-1:usoWYanY3Kpq2+kDIS2nhWoLZiRxanmdysdzqCFBHW4="
+FALLBACK_URL="https://cache.nixos.org/"
+FALLBACK_PUB_KEY="cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
+
+NIX_CONF="/etc/nix/nix.conf"
+KNOWN_HOSTS="/etc/ssh/ssh_known_hosts"
+MARKER_BEGIN="# BEGIN nix-cache client config (configure-nix-cache-client.sh)"
+MARKER_END="# END nix-cache client config"
+
+dry_run=0
+with_remote_builder=1
+restart_daemon=1
+
+for arg in "$@"; do
+  case "$arg" in
+    --dry-run) dry_run=1 ;;
+    --no-remote-builder) with_remote_builder=0 ;;
+    --no-restart) restart_daemon=0 ;;
+    -h|--help)
+      sed -n '2,20p' "$0"
+      exit 0
+      ;;
+    *)
+      echo "ERROR: unknown argument: $arg" >&2
+      exit 1
+      ;;
+  esac
+done
+
+if [[ "$dry_run" -eq 0 && "$EUID" -ne 0 ]]; then
+  echo "ERROR: must run as root (writes $NIX_CONF and, unless --no-remote-builder, $KNOWN_HOSTS)." >&2
+  exit 1
+fi
+
+if ! command -v nix >/dev/null 2>&1; then
+  echo "ERROR: no 'nix' binary on PATH -- install the Nix package manager first." >&2
+  exit 1
+fi
+
+if [[ ! -f "$NIX_CONF" ]]; then
+  echo "ERROR: $NIX_CONF not found -- expected an existing multi-user Nix install." >&2
+  exit 1
+fi
+
+builder_line=""
+if [[ "$with_remote_builder" -eq 1 ]]; then
+  if [[ -f "$REMOTE_BUILDER_KEY" ]]; then
+    case "$(uname -m)" in
+      x86_64) nix_system="x86_64-linux" ;;
+      aarch64) nix_system="aarch64-linux" ;;
+      *)
+        echo "WARNING: unrecognized architecture '$(uname -m)' -- skipping remote builder, keeping substituter config." >&2
+        with_remote_builder=0
+        ;;
+    esac
+    if [[ "$with_remote_builder" -eq 1 ]]; then
+      builder_line="builders = ssh://${REMOTE_BUILDER_USER}@${NIX_CACHE_HOST} ${nix_system} ${REMOTE_BUILDER_KEY} 4 2 big-parallel,kvm,nixos-test,benchmark"
+    fi
+  else
+    echo "WARNING: $REMOTE_BUILDER_KEY not found -- skipping remote builder config (substituter still configured)." >&2
+    echo "  See docs/nix-cache.md 'Remote builder SSH keys' for how to install it, then re-run this script." >&2
+    with_remote_builder=0
+  fi
+fi
+
+block="$(cat <<EOF
+$MARKER_BEGIN
+extra-substituters = http://${NIX_CACHE_HOST} ${FALLBACK_URL}
+extra-trusted-public-keys = ${CACHE_PUB_KEY} ${FALLBACK_PUB_KEY}
+EOF
+)"
+if [[ "$with_remote_builder" -eq 1 ]]; then
+  block="${block}
+builders-use-substitutes = true
+${builder_line}"
+fi
+block="${block}
+$MARKER_END"
+
+echo "== nix.conf block to install =="
+echo "$block"
+echo "================================"
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo "(--dry-run: not writing $NIX_CONF)"
+else
+  tmp_conf="$(mktemp)"
+  trap 'rm -f "$tmp_conf"' EXIT
+
+  if grep -qF "$MARKER_BEGIN" "$NIX_CONF"; then
+    awk -v begin="$MARKER_BEGIN" -v end="$MARKER_END" -v block="$block" '
+      $0 == begin { print block; skip = 1; next }
+      $0 == end   { skip = 0; next }
+      skip        { next }
+      { print }
+    ' "$NIX_CONF" > "$tmp_conf"
+  else
+    cp "$NIX_CONF" "$tmp_conf"
+    printf '\n%s\n' "$block" >> "$tmp_conf"
+  fi
+
+  cp "$NIX_CONF" "${NIX_CONF}.bak.$(date +%Y%m%d%H%M%S)"
+  install -m 0644 "$tmp_conf" "$NIX_CONF"
+  echo "Updated $NIX_CONF (backup saved alongside it)."
+fi
+
+if [[ "$with_remote_builder" -eq 1 ]]; then
+  known_hosts_line="${NIX_CACHE_HOST} ${NIX_CACHE_HOST_KEY}"
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "(--dry-run: would ensure this line is present in $KNOWN_HOSTS)"
+    echo "  $known_hosts_line"
+  else
+    mkdir -p "$(dirname "$KNOWN_HOSTS")"
+    touch "$KNOWN_HOSTS"
+    if ! grep -qF "$known_hosts_line" "$KNOWN_HOSTS" 2>/dev/null; then
+      echo "$known_hosts_line" >> "$KNOWN_HOSTS"
+      echo "Added nix-cache's SSH host key to $KNOWN_HOSTS."
+    fi
+  fi
+fi
+
+if [[ "$dry_run" -eq 0 && "$restart_daemon" -eq 1 ]]; then
+  if command -v systemctl >/dev/null 2>&1 && systemctl is-active --quiet nix-daemon 2>/dev/null; then
+    systemctl restart nix-daemon
+    echo "Restarted nix-daemon to pick up the new config."
+  else
+    echo "nix-daemon not managed by systemd (or not running) -- restart it manually to pick up the new config."
+  fi
+fi
+
+cat <<EOF
+
+Done. Verify with:
+  curl http://${NIX_CACHE_HOST}/nix-cache-info
+  nix show-config | grep -E 'substituters|trusted-public-keys|builders'
+EOF
+if [[ "$with_remote_builder" -eq 1 ]]; then
+  cat <<EOF
+  ssh -i ${REMOTE_BUILDER_KEY} ${REMOTE_BUILDER_USER}@${NIX_CACHE_HOST} nix-store --version
+  nix build nixpkgs#hello -L
+EOF
+fi
@@ -0,0 +1,858 @@
+#!/usr/bin/env bash
+# Creates new Proxmox VMs/LXC containers from this flake, and reconfigures
+# existing ones -- the manual workflows in docs/proxmox-images.md (VM) and
+# docs/auto-installer.md's "LXC hosts" section (container), automated.
+#
+# Images are built directly on the Proxmox node (PROXMOX_REMOTE_REPO_DIR /
+# --remote-repo-dir in scripts/env.sh), not on whatever machine runs this
+# script -- there's no multi-gigabyte image to transfer afterward. The first
+# time a node doesn't have that repo path yet, it's bootstrapped: cloned from
+# this checkout's own `origin` remote, then scripts/codex-setup.sh installs
+# the build tooling (Nix, etc.). Every run after that just `git pull`s it and
+# copies over the locally-managed host-keys/ (gitignored, so a git pull
+# alone wouldn't carry it) before building.
+#
+# --node (default: $PROXMOX_HOST, see scripts/env.sh) picks which of the two
+# LAN Proxmox nodes this runs against: production, pve1.sweet.home
+# ($PVE1_HOST, PROXMOX_HOST's own default), or the sandbox node,
+# pve-test.sweet.home ($PVE_TEST_HOST) -- pass --node "$PVE_TEST_HOST" (or
+# set PROXMOX_HOST=$PVE_TEST_HOST) to target the sandbox instead. See
+# CLAUDE.md's "Two Proxmox nodes" section: an agent session should default
+# to pve-test and only touch pve1 when the operator has explicitly said so
+# for the current task -- this script itself doesn't enforce that (its own
+# default is production, matching this repo's behavior before pve-test
+# existed), it's a policy for whoever/whatever is driving it.
+#
+# Usage:
+#   scripts/proxmox/create-proxmox-resource.sh --type lxc|vm --host <name> [options]
+#   scripts/proxmox/create-proxmox-resource.sh --type lxc|vm --list
+#   scripts/proxmox/create-proxmox-resource.sh --modify --vmid <n> [--cores N] [--memory MB] [--grow-disk GB]
+#
+# SAFETY:
+#   - The default (create) mode only ever creates a NEW resource -- it
+#     refuses to run if the target VMID already exists on the node, or if
+#     a VM/CT identified as --host already exists under any other VMID
+#     (checked live against the node; --allow-duplicate-host overrides).
+#   - --allow-duplicate-host distinguishes an exact match (same --type
+#     *and* --host, e.g. re-running --type lxc --host docker while an
+#     lxc-docker container already exists -- almost always a redeploy of
+#     the same target to pick up a rebuilt image) from a cross-type match
+#     (a different platform sharing the same host identity, e.g. a
+#     proxmox-docker VM coexisting with lxc-docker). Only the exact match
+#     is destroyed and replaced, after typing the hostname back to
+#     confirm (outside --dry-run) -- a cross-type match is always left
+#     untouched, matching-or-not.
+#   - --modify only ever touches a resource you name explicitly via
+#     --vmid, shows exactly what will change first, and (outside
+#     --dry-run) always requires typing that VMID back to confirm before
+#     anything is sent to the node. There is no bulk/implicit modify.
+#   - Outside of --allow-duplicate-host's exact-match replace above,
+#     neither mode can start/stop/delete a resource.
+#
+# See --help for the full option list.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=../lib/nix-eval.sh
+source "${repo_root}/scripts/lib/nix-eval.sh"
+# shellcheck source=../lib/confirm.sh
+source "${repo_root}/scripts/lib/confirm.sh"
+
+sync_keys="${repo_root}/scripts/secrets/sync-host-keys.sh"
+
+usage() {
+  cat <<EOF
+Usage: $0 --type lxc|vm --host <name> [options]      (create)
+       $0 --type lxc|vm --list                        (list --host values)
+       $0 --modify --vmid <n> [options]                (reconfigure)
+
+Create mode (default):
+  --type lxc|vm        lxc = container, built as a CT template tarball.
+                        vm  = VM, built as a Disko .raw disk image (UEFI/OVMF).
+  --host <name>         Which host identity to deploy -- matches
+                        config.networking.hostName (server, docker,
+                        nix-cache, nixos, pxe-boot, nix-minimal). Use
+                        --list to see what's available for --type.
+  --name <name>          Proxmox display name/hostname (default: --host's
+                          value, e.g. nix-cache -- for lxc this becomes the
+                          guest's real networking.hostName too, since
+                          proxmoxLXC.manageHostName pulls it from Proxmox's
+                          own container config, so it must match host.nix
+                          regardless of build type)
+  --vmid <n>              Numeric VMID (default: next free, via
+                          \`pvesh get /cluster/nextid\` on the node).
+                          Refuses to run if this ID already exists.
+  --disk-size <GB>           lxc only: rootfs size for \`pct create\`
+                              (default: \$PROXMOX_DEFAULT_LXC_DISK_GB, ${PROXMOX_DEFAULT_LXC_DISK_GB}).
+  --image <path>              Use this local image/tarball (uploaded to the
+                              node via scp) instead of checking the node /
+                              building one there from the flake.
+  --force-rebuild                Skip the "does the node already have this
+                                  image" check -- always build fresh and
+                                  overwrite what's there.
+  --remote-repo-dir <path>       Where this flake repo lives (or gets
+                                  cloned) on the node, and is built from
+                                  (default: \$PROXMOX_REMOTE_REPO_DIR, ${PROXMOX_REMOTE_REPO_DIR}).
+  --allow-duplicate-host        Required if a VM/CT identified as --host
+                                already exists on the node (checked live via
+                                qm/pct, not any file in this repo) --
+                                otherwise refused, since it'd share that
+                                host's hostName/hostId. An existing resource
+                                of this *same* --type (e.g. re-running --type
+                                lxc --host docker over an existing lxc-docker)
+                                is destroyed and replaced, after confirming --
+                                a different --type sharing the same --host
+                                (e.g. a proxmox-docker VM) is always left
+                                untouched.
+
+Modify mode (reconfigure an EXISTING resource -- requires --modify):
+  --modify                Switch to modify mode.
+  --vmid <n>                Required: which existing resource to change.
+                            Type/VM-vs-CT is auto-detected on the node.
+  --grow-disk <GB>            Grow the primary disk by this many GB
+                              (qm/pct resize; Proxmox only supports
+                              growing, never shrinking, an existing disk).
+  At least one of --cores / --memory / --grow-disk is required. Always
+  prints the current -> new values and requires typing the VMID back to
+  confirm, even outside --dry-run.
+
+Shared:
+  --cores <n>              create: default \$PROXMOX_DEFAULT_CORES (${PROXMOX_DEFAULT_CORES}).
+                            modify: omit to leave unchanged.
+  --memory <MB>              create: default \$PROXMOX_DEFAULT_MEMORY_MB (${PROXMOX_DEFAULT_MEMORY_MB}).
+                              modify: omit to leave unchanged.
+  --swap <MB>                 lxc only, create time: \`--memory\` doesn't
+                              touch swap -- it silently stays at Proxmox's
+                              own 512M default otherwise. (default: matches
+                              whatever --memory resolves to)
+  --storage <pool>              (default: \$PROXMOX_STORAGE, ${PROXMOX_STORAGE})
+  --iso-storage <pool>            (default: \$PROXMOX_ISO_STORAGE, ${PROXMOX_ISO_STORAGE})
+  --bridge <bridge>                (default: \$PROXMOX_BRIDGE, ${PROXMOX_BRIDGE})
+  --node <host>                     Proxmox node to SSH into (default:
+                                    \$PROXMOX_HOST, ${PROXMOX_HOST} --
+                                    production; the sandbox node is
+                                    \$PVE_TEST_HOST, ${PVE_TEST_HOST}).
+  --dry-run                           Print the full plan; touch nothing
+                                      local or remote, no prompts.
+  -h, --help
+
+Config for --storage/--bridge/--node/etc. lives in scripts/env.sh -- edit
+that instead of passing the same flag every time.
+EOF
+}
+
+dry_run=0
+modify=0
+type=""
+host=""
+name=""
+vmid=""
+cores=""
+memory=""
+swap=""
+disk_size=""
+grow_disk=""
+image=""
+storage="$PROXMOX_STORAGE"
+iso_storage="$PROXMOX_ISO_STORAGE"
+bridge="$PROXMOX_BRIDGE"
+node="$PROXMOX_HOST"
+remote_repo_dir="$PROXMOX_REMOTE_REPO_DIR"
+do_list=0
+allow_duplicate_host=0
+force_rebuild=0
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+  --type) type="$2"; shift 2 ;;
+  --host) host="$2"; shift 2 ;;
+  --name) name="$2"; shift 2 ;;
+  --vmid) vmid="$2"; shift 2 ;;
+  --cores) cores="$2"; shift 2 ;;
+  --memory) memory="$2"; shift 2 ;;
+  --swap) swap="$2"; shift 2 ;;
+  --disk-size) disk_size="$2"; shift 2 ;;
+  --grow-disk) grow_disk="$2"; shift 2 ;;
+  --image) image="$2"; shift 2 ;;
+  --storage) storage="$2"; shift 2 ;;
+  --iso-storage) iso_storage="$2"; shift 2 ;;
+  --bridge) bridge="$2"; shift 2 ;;
+  --node) node="$2"; shift 2 ;;
+  --remote-repo-dir) remote_repo_dir="$2"; shift 2 ;;
+  --list) do_list=1; shift ;;
+  --allow-duplicate-host) allow_duplicate_host=1; shift ;;
+  --force-rebuild) force_rebuild=1; shift ;;
+  --modify) modify=1; shift ;;
+  --dry-run) dry_run=1; shift ;;
+  -h | --help) usage; exit 0 ;;
+  *) echo "Unknown option: $1" >&2; usage >&2; exit 1 ;;
+  esac
+done
+
+ssh_target="${PROXMOX_SSH_USER}@${node}"
+
+remote() {
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] ssh ${ssh_target} -- $*"
+  else
+    ssh "$ssh_target" "$@"
+  fi
+}
+
+# ============================================================ modify mode
+cmd_modify() {
+  if [[ -z "$vmid" ]]; then
+    echo "ERROR: --modify requires --vmid." >&2
+    exit 1
+  fi
+  if [[ -z "$cores" && -z "$memory" && -z "$grow_disk" ]]; then
+    echo "ERROR: --modify needs at least one of --cores / --memory / --grow-disk." >&2
+    exit 1
+  fi
+
+  echo "Looking up VMID ${vmid} on ${node}..."
+  local kind current_cores current_memory disk_key
+  if ssh "$ssh_target" "qm status ${vmid}" >/dev/null 2>&1; then
+    kind="vm"
+    disk_key="scsi0"
+  elif ssh "$ssh_target" "pct status ${vmid}" >/dev/null 2>&1; then
+    kind="lxc"
+    disk_key="rootfs"
+  else
+    echo "ERROR: VMID ${vmid} doesn't exist on ${node} -- nothing to modify." >&2
+    exit 1
+  fi
+
+  local config_cmd="qm config ${vmid}"
+  [[ "$kind" == "lxc" ]] && config_cmd="pct config ${vmid}"
+  local current_config
+  current_config="$(ssh "$ssh_target" "$config_cmd")"
+  current_cores="$(echo "$current_config" | grep -oP '^cores:\s*\K\S+' || echo '?')"
+  current_memory="$(echo "$current_config" | grep -oP '^memory:\s*\K\S+' || echo '?')"
+
+  echo
+  echo "VMID ${vmid} is a ${kind} on ${node}. Planned changes:"
+  [[ -n "$cores" ]] && echo "  cores:  ${current_cores} -> ${cores}"
+  [[ -n "$memory" ]] && echo "  memory: ${current_memory} MB -> ${memory} MB"
+  [[ -n "$grow_disk" ]] && echo "  ${disk_key}: grow by +${grow_disk}G (Proxmox can only grow, not shrink, an existing disk)"
+
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo
+    echo "[dry-run] Nothing was changed."
+    return
+  fi
+
+  echo
+  if ! confirm_typed "$vmid" "Type the VMID (${vmid}) to confirm these changes: "; then
+    echo "Cancelled -- input didn't match ${vmid}."
+    exit 1
+  fi
+
+  local set_cmd="qm set"
+  local resize_cmd="qm resize"
+  [[ "$kind" == "lxc" ]] && set_cmd="pct set" && resize_cmd="pct resize"
+
+  if [[ -n "$cores" || -n "$memory" ]]; then
+    local args=""
+    [[ -n "$cores" ]] && args="${args} --cores ${cores}"
+    [[ -n "$memory" ]] && args="${args} --memory ${memory}"
+    remote "${set_cmd} ${vmid}${args}"
+  fi
+  if [[ -n "$grow_disk" ]]; then
+    remote "${resize_cmd} ${vmid} ${disk_key} +${grow_disk}G"
+  fi
+
+  echo
+  echo "Done. VMID ${vmid} updated."
+}
+
+if [[ "$modify" -eq 1 ]]; then
+  cmd_modify
+  exit 0
+fi
+
+# ============================================================= create mode
+if [[ "$type" != "lxc" && "$type" != "vm" ]]; then
+  echo "ERROR: --type must be 'lxc' or 'vm'." >&2
+  usage >&2
+  exit 1
+fi
+
+platform_prefix="lxc"
+[[ "$type" == "vm" ]] && platform_prefix="proxmox"
+[[ -z "$cores" ]] && cores="$PROXMOX_DEFAULT_CORES"
+[[ -z "$memory" ]] && memory="$PROXMOX_DEFAULT_MEMORY_MB"
+
+# --- discover / resolve the flake target from --host --------------------
+# Emits "<target>\t<hostName>" pairs for every ${platform_prefix}-* flake
+# target -- the one source both --list and the --host lookup below read
+# from, so they can never see a different set of targets from each other.
+targets_for_platform() {
+  local target
+  for target in $(list_flake_targets "$repo_root" 2>/dev/null | grep -- "^${platform_prefix}-"); do
+    printf '%s\t%s\n' "$target" "$(flake_target_hostname "$repo_root" "$target")"
+  done
+}
+
+list_hosts() {
+  local target hostname
+  while IFS=$'\t' read -r target hostname; do
+    printf '  %-12s -> %s\n' "$hostname" "$target"
+  done < <(targets_for_platform)
+}
+
+if [[ "$do_list" -eq 1 ]]; then
+  echo "Available --host values for --type ${type}:"
+  list_hosts
+  exit 0
+fi
+
+if [[ -z "$host" ]]; then
+  echo "ERROR: --host is required (or use --list to see options)." >&2
+  exit 1
+fi
+
+flake_target=""
+while IFS=$'\t' read -r target hostname; do
+  if [[ "$hostname" == "$host" ]]; then
+    flake_target="$target"
+    break
+  fi
+done < <(targets_for_platform)
+
+if [[ -z "$flake_target" ]]; then
+  echo "ERROR: no ${platform_prefix}-* target has hostName '${host}'." >&2
+  echo "Available:" >&2
+  list_hosts >&2
+  exit 1
+fi
+
+# The container/VM's real identity is --host (e.g. "nix-cache"), validated
+# above against config.networking.hostName -- not the flake target name
+# (e.g. "lxc-nix-cache"), which is build-type-specific and only exists to
+# pick which platform variant to build. Defaulting --name to the flake
+# target would make lxc's --hostname (which proxmoxLXC.manageHostName
+# feeds straight into the guest's real hostname) disagree with host.nix.
+[[ -z "$name" ]] && name="$host"
+
+# --- refuse to duplicate a host that's already live on the node ---------
+# Queries the node itself (qm/pct's own name/hostname config), not any
+# static list in this repo -- a file can't track whether a resource still
+# actually exists, and this used to be checked against variables.nix's
+# deployedTargets, which drifted stale (it kept naming a VM as "the real
+# deployment" well after that VM had been destroyed, blocking its own
+# redeploy) until that list was dropped in favour of this live check. This
+# only catches guests identified with the default --name (== --host, what
+# this script itself always uses unless --name is overridden) -- a guest
+# manually renamed on the node afterwards wouldn't match, but nothing here
+# creates guests that way.
+if [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] would check ${node} for an existing VM/CT identified as '${host}'"
+  if [[ "$allow_duplicate_host" -eq 1 ]]; then
+    echo "[dry-run] --allow-duplicate-host: an existing ${type} named '${host}' would be" \
+      "destroyed and replaced; a different-type match would be left untouched"
+  fi
+else
+  echo
+  echo "==> Checking ${node} for an existing VM/CT identified as '${host}'..."
+  ssh_check_status=0
+  existing="$(ssh "$ssh_target" bash -s -- "$host" <<'REMOTE_SCRIPT'
+target="$1"
+for id in $(qm list 2>/dev/null | awk 'NR>1{print $1}'); do
+  n="$(qm config "$id" 2>/dev/null | grep -oP '^name:\s*\K\S+' || true)"
+  [[ "$n" == "$target" ]] && echo "vm ${id} ${n}"
+done
+for id in $(pct list 2>/dev/null | awk 'NR>1{print $1}'); do
+  n="$(pct config "$id" 2>/dev/null | grep -oP '^hostname:\s*\K\S+' || true)"
+  [[ "$n" == "$target" ]] && echo "lxc ${id} ${n}"
+done
+exit 0
+REMOTE_SCRIPT
+  )" || ssh_check_status=$?
+  if [[ "$ssh_check_status" -ne 0 ]]; then
+    echo "ERROR: couldn't reach ${node} (ssh exited ${ssh_check_status}) to check for an" >&2
+    echo "existing '${host}' resource -- refusing to guess. Fix connectivity and retry," >&2
+    echo "or pass --allow-duplicate-host if you're sure none exists (this skips the" >&2
+    echo "check entirely)." >&2
+    exit 1
+  fi
+
+  # Split into "exact" (same resource kind as --type -- i.e. literally this
+  # same host+platform combo already exists, almost always a redeploy of
+  # the same target to test a rebuilt image) vs "cross-type" (a different
+  # platform sharing this host identity, e.g. a stopped proxmox-docker VM
+  # coexisting with an lxc-docker container -- a deliberate, valid setup
+  # this script has never managed and still won't). Read via a herestring
+  # (not a pipe) so the appends below survive outside the loop.
+  this_kind="$type"
+  exact_matches=""
+  cross_matches=""
+  if [[ -n "$existing" ]]; then
+    while read -r kind id n; do
+      [[ -z "$kind" ]] && continue
+      if [[ "$kind" == "$this_kind" ]]; then
+        exact_matches+="${kind} ${id} ${n}"$'\n'
+      else
+        cross_matches+="${kind} ${id} ${n}"$'\n'
+      fi
+    done <<<"$existing"
+  fi
+
+  if [[ -n "$exact_matches" && "$allow_duplicate_host" -ne 1 ]]; then
+    echo "ERROR: '${host}' already exists on ${node} as this same resource type:" >&2
+    echo "$exact_matches" | while read -r kind id n; do
+      [[ -z "$kind" ]] && continue
+      echo "  - ${kind} VMID ${id} (${n})" >&2
+    done
+    echo "Refusing to create a second ${this_kind} sharing this identity. Pass" >&2
+    echo "--allow-duplicate-host to destroy it and create a fresh one in its place" >&2
+    echo "(after confirming), or use --modify to reconfigure the existing one instead." >&2
+    exit 1
+  fi
+
+  if [[ -n "$cross_matches" && "$allow_duplicate_host" -ne 1 ]]; then
+    echo "ERROR: '${host}' already exists on ${node} as a different resource type:" >&2
+    echo "$cross_matches" | while read -r kind id n; do
+      [[ -z "$kind" ]] && continue
+      echo "  - ${kind} VMID ${id} (${n})" >&2
+    done
+    echo "Refusing to create a second resource sharing this identity. Pass" >&2
+    echo "--allow-duplicate-host to create one anyway (it gets its own distinct" >&2
+    echo "sops key and VMID -- the existing resource above is left untouched)," >&2
+    echo "or use --modify to reconfigure the existing one instead." >&2
+    exit 1
+  fi
+
+  if [[ -n "$cross_matches" ]]; then
+    echo "--allow-duplicate-host: '${host}' also exists on ${node} as a different resource" \
+      "type -- leaving it untouched:"
+    echo "$cross_matches" | while read -r kind id n; do
+      [[ -z "$kind" ]] && continue
+      echo "  - ${kind} VMID ${id} (${n})"
+    done
+  fi
+
+  if [[ -n "$exact_matches" ]]; then
+    echo "--allow-duplicate-host: '${host}' already exists on ${node} as this same resource" \
+      "type -- it will be destroyed and replaced:"
+    echo "$exact_matches" | while read -r kind id n; do
+      [[ -z "$kind" ]] && continue
+      echo "  - ${kind} VMID ${id} (${n})"
+    done
+    echo
+    if ! confirm_typed "$host" "Type the hostname (${host}) to confirm destroying the above and replacing it: "; then
+      echo "Cancelled -- input didn't match ${host}." >&2
+      exit 1
+    fi
+    echo "$exact_matches" | while read -r kind id n; do
+      [[ -z "$kind" ]] && continue
+      echo "==> Destroying ${kind} VMID ${id} (${n})..."
+      if [[ "$kind" == "vm" ]]; then
+        # qm destroy has no --force to stop-then-destroy in one call (pct's
+        # does) -- stop explicitly first if it's running.
+        if ssh "$ssh_target" "qm status ${id}" 2>/dev/null | grep -q running; then
+          ssh "$ssh_target" "qm stop ${id}"
+        fi
+        ssh "$ssh_target" "qm destroy ${id} --purge 1"
+      else
+        ssh "$ssh_target" "pct destroy ${id} --force 1 --purge 1"
+      fi
+    done
+  fi
+fi
+
+echo "Target: ${flake_target} (host=${host}, type=${type}) -> Proxmox resource '${name}'"
+
+# Decide on nix-cache once, here -- this is the earliest point that needs
+# it (sync-host-keys.sh below needs nix-shell packages regardless of
+# whether an image ends up getting built later), and the decision is
+# exported so that subprocess -- and this script's own later build step,
+# if it gets there -- both reuse it instead of probing again.
+nix_extra_opts
+
+# --- make sure this target has a registered host key --------------------
+echo
+echo "==> Ensuring host key exists and is registered..."
+sync_args=("$flake_target")
+[[ "$dry_run" -eq 1 ]] && sync_args+=(--dry-run)
+bash "$sync_keys" "${sync_args[@]}"
+
+# --- VMID: pick one, and refuse to touch anything that already exists ---
+echo
+if [[ -z "$vmid" ]]; then
+  if [[ "$dry_run" -eq 1 ]]; then
+    vmid="<next-free-vmid>"
+    echo "[dry-run] would ask ${node} for the next free VMID (pvesh get /cluster/nextid)"
+  else
+    vmid="$(ssh "$ssh_target" "pvesh get /cluster/nextid" | tr -d '[:space:]')"
+    echo "Auto-assigned VMID: ${vmid}"
+  fi
+else
+  echo "Requested VMID: ${vmid}"
+fi
+
+if [[ "$dry_run" -eq 0 ]]; then
+  # qm/pct status exits non-zero (and prints "does not exist") for a free
+  # ID on that resource type -- but a VMID could exist as the OTHER
+  # resource type (e.g. requested a CT id that's actually a VM), so check
+  # both. Any success here means something is already using this ID --
+  # refuse to go anywhere near it. (Reconfiguring an existing resource is
+  # --modify's job, not this one's.)
+  if ssh "$ssh_target" "qm status ${vmid}" >/dev/null 2>&1 \
+    || ssh "$ssh_target" "pct status ${vmid}" >/dev/null 2>&1; then
+    echo "ERROR: VMID ${vmid} already exists on ${node}. Refusing to touch an" >&2
+    echo "existing resource here -- use --modify to reconfigure it, pick a" >&2
+    echo "different --vmid, or omit it to auto-assign." >&2
+    exit 1
+  fi
+fi
+
+# --- resolve the remote path -- fixed naming (not the nix store's own
+# derivation-hash-based filename), so a later run can check for it by name.
+# lxc uploads as a CT *template* (Proxmox's "vztmpl" content type, under
+# iso_storage) -- config.system.build.tarball is a plain rootfs tarball,
+# not a vzdump backup archive, so it's created with `pct create ... vztmpl`,
+# not restored with `pct restore` (that expects backup-archive metadata
+# this tarball doesn't have, and fails with "archive contains no
+# configuration file").
+remote_dir="/var/lib/vz/import"
+remote_filename="${flake_target}.raw"
+if [[ "$type" == "lxc" ]]; then
+  remote_dir="/var/lib/vz/template/cache"
+  remote_filename="${flake_target}.tar.xz"
+fi
+remote_path="${remote_dir}/${remote_filename}"
+
+# --- ensure the flake repo (+ tooling) exists on the node, and is current --
+# Bootstraps once (git clone from this checkout's own `origin`, then
+# scripts/codex-setup.sh installs Nix + friends) if ${remote_repo_dir}
+# doesn't exist yet on the node; otherwise just `git pull`s it, so the image
+# built there reflects what's actually committed and pushed. Only called
+# right before an actual remote build below -- reusing an image already on
+# the node, or an explicit --image, never touch the node's checkout at all.
+ensure_remote_repo() {
+  echo
+  echo "==> Ensuring ${remote_repo_dir} exists and is current on ${node}..."
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] would ensure ${remote_repo_dir} exists on ${node} (clone if missing, git pull if present), and would verify/bootstrap build tooling there (scripts/codex-setup.sh) if \`nix\` isn't already on PATH -- and if that bootstrap actually ran, would also configure ${node} as a nix-cache client (scripts/proxmox/configure-nix-cache-client.sh)"
+    return
+  fi
+
+  if ssh "$ssh_target" "test -d '${remote_repo_dir}/.git'"; then
+    echo "Repo present -- pulling latest..."
+    ssh "$ssh_target" "cd '${remote_repo_dir}' && git pull --ff-only"
+  else
+    local origin_url
+    origin_url="$(git -C "$repo_root" remote get-url origin 2>/dev/null || true)"
+    if [[ -z "$origin_url" ]]; then
+      echo "ERROR: ${remote_repo_dir} doesn't exist on ${node}, and this checkout has no" >&2
+      echo "'origin' remote to clone from. Set one (git remote add origin <url>) or create" >&2
+      echo "${remote_repo_dir} on ${node} yourself (e.g. git clone), then re-run." >&2
+      exit 1
+    fi
+    echo "Not present -- cloning from ${origin_url}..."
+    ssh "$ssh_target" "git clone '${origin_url}' '${remote_repo_dir}'"
+  fi
+
+  # Trivial check, run every time (not just right after a fresh clone) --
+  # confirmed live: a first bootstrap can clone the repo successfully and
+  # still leave the node without a working `nix` (e.g. the node had no
+  # `sudo`, which the Nix installer's root path depends on -- see the fix
+  # in scripts/codex-setup.sh), and a later run with the repo already
+  # present would otherwise never retry it. Sources
+  # scripts/lib/nix-bootstrap.sh's ensure_nix_profile first -- a
+  # single-user Nix install typically only gets sourced into login shells,
+  # and ssh's non-interactive command execution is neither, so a
+  # freshly-installed `nix` still wouldn't be on PATH here without it.
+  #
+  # Just `nix` today -- the only thing the remote build commands below
+  # actually invoke -- but a list (not a single hardcoded check) so a
+  # future remote step needing another tool can add itself here instead of
+  # growing a parallel check.
+  local remote_required_cmds=(nix)
+  local tooling_check_cmd="cd '${remote_repo_dir}' && . scripts/lib/nix-bootstrap.sh && ensure_nix_profile"
+  local cmd
+  for cmd in "${remote_required_cmds[@]}"; do
+    tooling_check_cmd="${tooling_check_cmd} && command -v ${cmd}"
+  done
+
+  if ssh "$ssh_target" "$tooling_check_cmd" >/dev/null 2>&1; then
+    echo "Build tooling already present on ${node}."
+  else
+    echo "==> Bootstrapping build tooling on ${node} (scripts/codex-setup.sh)..."
+    ssh "$ssh_target" "cd '${remote_repo_dir}' && bash scripts/codex-setup.sh"
+
+    # Only on this first-time bootstrap, not every run -- a node that
+    # already has tooling either already went through this once, or had
+    # it configured some other way, and re-running is harmless but
+    # pointless. Non-fatal: this only makes the node's own builds faster
+    # (substitute from nix-cache instead of building from source) and
+    # offloadable to it as a remote builder -- worth trying, not worth
+    # aborting the image build over if nix-cache happens to be down right
+    # now. Needs ensure_nix_profile first, same as the tooling_check_cmd
+    # above -- ssh's non-interactive command execution won't have picked
+    # up a freshly single-user-installed `nix` otherwise.
+    echo "==> Configuring ${node} as a nix-cache substituter/remote-builder client..."
+    if ! ssh "$ssh_target" "cd '${remote_repo_dir}' && . scripts/lib/nix-bootstrap.sh && ensure_nix_profile && bash scripts/proxmox/configure-nix-cache-client.sh"; then
+      echo "WARNING: configure-nix-cache-client.sh failed on ${node} -- continuing without it (${node} will build from source / against cache.nixos.org only)." >&2
+    fi
+  fi
+}
+
+# --- sync locally-managed host-keys/ to the node ---------------------------
+# Gitignored (see .gitignore), so `git pull` above never carries it -- both
+# build paths need it present as NIXOS_HOST_KEYS_DIR / --pre-format-files
+# input on the node itself now that the build runs there. scp (not rsync,
+# not already a dependency anywhere else in this repo) mirrors how this
+# script already transfers the --image case below.
+sync_remote_host_keys() {
+  echo
+  echo "==> Syncing host-keys/ to ${node}..."
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] would copy ${repo_root}/host-keys/ to ${ssh_target}:${remote_repo_dir}/host-keys/"
+    return
+  fi
+  ssh "$ssh_target" "mkdir -p '${remote_repo_dir}/host-keys'"
+  scp -pr "${repo_root}/host-keys/." "${ssh_target}:${remote_repo_dir}/host-keys/"
+}
+
+# --- build (or reuse an image already on the node) ------------------------
+echo
+local_image=""
+image_already_remote=0
+
+if [[ -n "$image" ]]; then
+  [[ -f "$image" ]] || { echo "ERROR: --image '${image}' not found." >&2; exit 1; }
+  local_image="$image"
+  echo "Using provided image: ${local_image}"
+elif [[ "$force_rebuild" -eq 1 ]]; then
+  echo "--force-rebuild: skipping the existing-image check on ${node}."
+else
+  echo "==> Checking whether ${node} already has ${remote_path}..."
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] would check: ssh ${ssh_target} -- test -f ${remote_path}"
+  elif ssh "$ssh_target" "test -f '${remote_path}'" 2>/dev/null; then
+    echo "Found it -- reusing, skipping build (use --force-rebuild to override)."
+    image_already_remote=1
+  else
+    echo "Not found -- will build."
+  fi
+fi
+
+if [[ "$image_already_remote" -eq 0 && -z "$local_image" ]]; then
+  ensure_remote_repo
+  sync_remote_host_keys
+
+  # Relayed into the remote build below exactly as decided by the local
+  # nix_extra_opts call earlier in this script -- that decision (whether
+  # nix-cache is reachable) is made once, locally, same as it always has
+  # been; only *where* the resulting "${NIX_OPTS[@]}" gets used as a `nix
+  # build` flag moves to the node. NIX_EXTRA_OPTS is already a %q-quoted
+  # string built for exactly this eval-based reconstruction (see env.sh).
+  nix_opts_display=""
+  if [[ ${#NIX_OPTS[@]} -gt 0 ]]; then
+    printf -v nix_opts_display '%q ' "${NIX_OPTS[@]}"
+    nix_opts_display=" ${nix_opts_display% }"
+  fi
+
+  if [[ "$type" == "lxc" ]]; then
+    if [[ "$dry_run" -eq 1 ]]; then
+      echo "[dry-run] would build on ${node}: NIXOS_HOST_KEYS_DIR=\$(pwd)/host-keys nix build --impure \\"
+      echo "[dry-run]   --no-use-registries --no-accept-flake-config${nix_opts_display} \\"
+      echo "[dry-run]   .#nixosConfigurations.${flake_target}.config.system.build.tarball"
+      echo "[dry-run] would stage the result at ${remote_path}"
+      local_image="<built-tarball>"
+    else
+      echo "==> Building LXC tarball for ${flake_target} on ${node}..."
+      # Built as a single already-%q-quoted command string, not separate ssh
+      # argv elements -- ssh joins remote command args with plain spaces and
+      # hands the result to the remote shell to re-split, which would
+      # otherwise scatter NIX_EXTRA_OPTS (itself several space-separated,
+      # %q-quoted tokens) across the wrong positional parameters below.
+      printf -v remote_cmd 'bash -s -- %q %q %q %q %q' \
+        "$remote_repo_dir" "$flake_target" "$remote_dir" "$remote_filename" "$NIX_EXTRA_OPTS"
+      ssh "$ssh_target" "$remote_cmd" <<'REMOTE_SCRIPT'
+set -euo pipefail
+repo_dir="$1"; target="$2"; dest_dir="$3"; dest_name="$4"; nix_extra_opts_str="$5"
+declare -a NIX_OPTS=()
+[[ -n "$nix_extra_opts_str" ]] && eval "NIX_OPTS=(${nix_extra_opts_str})"
+cd "$repo_dir"
+# A single-user Nix install only gets sourced into login shells; this ssh
+# session is neither, so `nix` wouldn't otherwise be on PATH here even
+# right after a successful install.
+. scripts/lib/nix-bootstrap.sh
+ensure_nix_profile
+NIXOS_HOST_KEYS_DIR="$(pwd)/host-keys" nix build --impure \
+  --no-use-registries --no-accept-flake-config "${NIX_OPTS[@]}" \
+  ".#nixosConfigurations.${target}.config.system.build.tarball" \
+  --out-link "result-${target}"
+built="$(find "result-${target}/tarball" -maxdepth 1 -type f | head -1)"
+if [[ -z "$built" ]]; then
+  echo "ERROR: no tarball found under result-${target}/tarball after build." >&2
+  exit 1
+fi
+mkdir -p "$dest_dir"
+cp "$built" "${dest_dir}/${dest_name}"
+echo "Built and staged: ${dest_dir}/${dest_name}"
+REMOTE_SCRIPT
+      local_image="$remote_path"
+      echo "Built on ${node}: ${remote_path}"
+    fi
+  else
+    # PROXMOX_SSH_USER defaults to root (env.sh), which needs no sudo and
+    # can't assume it's even installed on a minimal node -- only shell out
+    # through sudo when actually running as a non-root SSH user.
+    sudo_prefix="sudo"
+    sudo_display="sudo "
+    if [[ "$PROXMOX_SSH_USER" == "root" ]]; then
+      sudo_prefix=""
+      sudo_display=""
+    fi
+    if [[ "$dry_run" -eq 1 ]]; then
+      echo "[dry-run] would build on ${node}: nix build --no-use-registries --no-accept-flake-config${nix_opts_display} \\"
+      echo "[dry-run]   .#nixosConfigurations.${flake_target}.config.system.build.diskoImagesScript"
+      echo "[dry-run] would run:   ${sudo_display}./result-${flake_target} \\"
+      echo "[dry-run]                --pre-format-files host-keys/${flake_target}_ssh_host_ed25519_key /etc/ssh/ssh_host_ed25519_key \\"
+      echo "[dry-run]                --pre-format-files host-keys/${flake_target}_ssh_host_ed25519_key.pub /etc/ssh/ssh_host_ed25519_key.pub \\"
+      echo "[dry-run]                --build-memory 2048"
+      echo "[dry-run] would stage the result at ${remote_path}"
+      local_image="<built-image>.raw"
+    else
+      echo "==> Building Disko image for ${flake_target} on ${node}..."
+      # See the LXC branch above for why this is one %q-quoted command
+      # string rather than separate ssh argv elements.
+      printf -v remote_cmd 'bash -s -- %q %q %q %q %q %q' \
+        "$remote_repo_dir" "$flake_target" "$remote_dir" "$remote_filename" "$NIX_EXTRA_OPTS" "$sudo_prefix"
+      ssh "$ssh_target" "$remote_cmd" <<'REMOTE_SCRIPT'
+set -euo pipefail
+repo_dir="$1"; target="$2"; dest_dir="$3"; dest_name="$4"; nix_extra_opts_str="$5"; sudo_prefix="$6"
+declare -a NIX_OPTS=()
+[[ -n "$nix_extra_opts_str" ]] && eval "NIX_OPTS=(${nix_extra_opts_str})"
+cd "$repo_dir"
+. scripts/lib/nix-bootstrap.sh
+ensure_nix_profile
+nix build --no-use-registries --no-accept-flake-config "${NIX_OPTS[@]}" \
+  ".#nixosConfigurations.${target}.config.system.build.diskoImagesScript" \
+  --out-link "result-${target}"
+$sudo_prefix "./result-${target}" \
+  --pre-format-files "host-keys/${target}_ssh_host_ed25519_key" /etc/ssh/ssh_host_ed25519_key \
+  --pre-format-files "host-keys/${target}_ssh_host_ed25519_key.pub" /etc/ssh/ssh_host_ed25519_key.pub \
+  --build-memory 2048
+built="$(find . -maxdepth 1 -name '*.raw' -newer "result-${target}" | head -1)"
+if [[ -z "$built" ]]; then
+  echo "ERROR: no .raw image found in ${repo_dir} after build." >&2
+  exit 1
+fi
+mkdir -p "$dest_dir"
+mv "$built" "${dest_dir}/${dest_name}"
+echo "Built and staged: ${dest_dir}/${dest_name}"
+REMOTE_SCRIPT
+      local_image="$remote_path"
+      echo "Built on ${node}: ${remote_path}"
+    fi
+  fi
+fi
+
+# --- upload -- only for an explicit --image; a build above stages its
+# result directly at ${remote_path} on the node already, and reusing an
+# image already on the node needs nothing transferred either. ------------
+echo
+if [[ -n "$image" ]]; then
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] would upload: scp ${local_image} ${ssh_target}:${remote_path}"
+  else
+    echo "==> Uploading to ${node}:${remote_path}..."
+    ssh "$ssh_target" "mkdir -p ${remote_dir}"
+    scp "$local_image" "${ssh_target}:${remote_path}"
+  fi
+fi
+
+# --- create -----------------------------------------------------------------
+echo
+if [[ "$type" == "lxc" ]]; then
+  echo "==> Creating LXC container ${vmid} (${name})..."
+  local_disk_size="${disk_size:-$PROXMOX_DEFAULT_LXC_DISK_GB}"
+  # --memory doesn't touch swap -- it silently stays at Proxmox's own
+  # 512M default otherwise (confirmed live: --memory 2048 left swap at
+  # 512). Default to matching whatever --memory resolved to above.
+  local_swap="${swap:-$memory}"
+  # --unprivileged: read back from modules/platforms/lxc.nix's own
+  # proxmoxLXC.privileged (via flake_target_lxc_privileged) rather than
+  # hardcoded, since that's no longer the same for every lxc-* target --
+  # lxc-docker sets it true so the container's NFS mounts work at all (the
+  # kernel's NFS client can't mount from inside any unprivileged
+  # container's user namespace, no matter what AppArmor allows -- see that
+  # option's own comment). The NixOS config inside the image bakes in
+  # cgroup/capability/mount expectations matching whichever value it was
+  # built with, so this must stay in sync with it -- `pct create`'s own
+  # CLI default for this flag is privileged (unlike the web UI, which
+  # defaults its checkbox the other way), so leaving it unset would create
+  # a privileged container running a NixOS config that assumes
+  # unprivileged for every target except lxc-docker, a real mismatch.
+  privileged_eval="$(flake_target_lxc_privileged "$repo_root" "$flake_target")"
+  unprivileged_flag=1
+  [[ "$privileged_eval" == "true" ]] && unprivileged_flag=0
+  #
+  # --features nesting=1,keyctl=1: required for a modern (v247+) systemd
+  # guest to actually boot unprivileged -- confirmed live: without this,
+  # AppArmor denies the nested user namespaces and credential mounts
+  # systemd routinely uses (even plain getty units), and every getty
+  # crash-loops on a denied mount every ~3s (visible as garbage on the
+  # console) while core services like nsncd fail the same way.
+  #
+  # ...,mount=nfs;nfs4: without it AppArmor blanket-denies the `nfs`/
+  # `rpc_pipefs` mount syscalls any NFS client share needs -- confirmed
+  # live on lxc-docker: `mount: /var/lib/nfs/rpc_pipefs: permission
+  # denied`. The value's `;` (Proxmox's own multi-fstype separator for
+  # this one feature, per PVE::LXC's use of PVE::ParseUtils::split_list)
+  # must stay single-quoted here: create_cmd is sent to `remote()`, which
+  # hands the whole string to `ssh` as a single command for the *remote*
+  # shell to parse -- unquoted, that `;` would be read as a remote
+  # command separator and silently truncate this into two commands.
+  create_cmd="pct create ${vmid} ${iso_storage}:vztmpl/${remote_filename} --unprivileged ${unprivileged_flag} --features '${PROXMOX_DEFAULT_LXC_FEATURES}' --rootfs ${storage}:${local_disk_size} --hostname ${name} --cores ${cores} --memory ${memory} --swap ${local_swap} --net0 name=eth0,bridge=${bridge},ip=dhcp"
+  remote "$create_cmd"
+  remote "pct start ${vmid}"
+else
+  echo "==> Creating VM ${vmid} (${name})..."
+  # pre-enrolled-keys=0 disables OVMF's Secure Boot key pre-enrollment --
+  # required, or systemd-boot (unsigned) can't be trusted by the firmware.
+  # --agent 1: wires up the virtio-serial channel QEMU exposes to the guest.
+  # modules/common/configuration.nix sets services.qemuGuest.enable = true
+  # on every host, so the guest-side qemu-ga daemon is already running --
+  # without this flag Proxmox never creates the channel it listens on, so
+  # `qm guest exec`/`qm agent` and the UI's IP-address display silently
+  # never work for any VM this script creates.
+  remote "qm create ${vmid} --name ${name} --memory ${memory} --cores ${cores} \
+--net0 virtio,bridge=${bridge} --bios ovmf --machine q35 --scsihw virtio-scsi-pci \
+--efidisk0 ${storage}:1,efitype=4m,pre-enrolled-keys=0 --agent enabled=1"
+
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] ssh ${ssh_target} -- qm importdisk ${vmid} ${remote_path} ${storage}"
+    echo "[dry-run] (would parse the resulting disk identifier from that output)"
+    echo "[dry-run] ssh ${ssh_target} -- qm set ${vmid} --scsi0 ${storage}:<parsed-disk-id>"
+  else
+    importdisk_output="$(ssh "$ssh_target" "qm importdisk ${vmid} ${remote_path} ${storage}")"
+    echo "$importdisk_output"
+    disk_id="$(echo "$importdisk_output" | grep -oP "(?<=Successfully imported disk as ')[^']+" | sed 's/^unused[0-9]*://')"
+    if [[ -z "$disk_id" ]]; then
+      echo "ERROR: couldn't parse the imported disk identifier from qm importdisk's output above." >&2
+      echo "The VM shell (${vmid}) and imported disk both exist -- finish attaching it by hand:" >&2
+      echo "  ssh ${ssh_target} -- qm set ${vmid} --scsi0 ${storage}:<disk-id-from-output-above>" >&2
+      echo "  ssh ${ssh_target} -- qm set ${vmid} --boot order=scsi0" >&2
+      exit 1
+    fi
+    remote "qm set ${vmid} --scsi0 ${disk_id}"
+  fi
+  remote "qm set ${vmid} --boot order=scsi0"
+  remote "qm start ${vmid}"
+fi
+
+echo
+if [[ "$dry_run" -eq 1 ]]; then
+  echo "[dry-run] Nothing was built, uploaded, or created."
+else
+  echo "Done. ${name} (VMID ${vmid}) should be booting on ${node}."
+fi
@@ -0,0 +1,150 @@
+#!/usr/bin/env bash
+# Backs up the local sops age key (the private key that decrypts
+# secrets/*.yaml -- normally the one trusted as &admin) to an arbitrary
+# destination path, e.g. a USB drive or other offline storage, so it can
+# later be restored and handed to rotate-admin-key.sh if this machine's
+# copy is ever lost, or to run either script from a different machine.
+#
+# Usage:
+#   scripts/secrets/backup-admin-key.sh <dest-path> [--key-file <path>] [--force] [--dry-run]
+#
+# Source key resolution matches sops/age's own default order:
+#   $SOPS_AGE_KEY (inline identity text) if set, else
+#   --key-file if given, else
+#   $SOPS_AGE_KEY_FILE if set, else
+#   ${XDG_CONFIG_HOME:-$HOME/.config}/sops/age/keys.txt
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+sops_yaml="${repo_root}/.sops.yaml"
+
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=../lib/sops-age.sh
+source "${repo_root}/scripts/lib/sops-age.sh"
+
+# Pin cwd for the same reason rotate-admin-key.sh does: age/sops calls
+# below should never depend on wherever the caller's shell happened to be.
+cd "$repo_root"
+
+usage() {
+  cat <<EOF
+Usage: $0 <dest-path> [--key-file <path>] [--force] [--dry-run]
+
+  <dest-path>        Where to write the backup. Parent directories are
+                     created as needed. Written with 0600 permissions.
+  --key-file <path>  Read the key from here instead of the default
+                     sops/age resolution (\$SOPS_AGE_KEY_FILE, then
+                     \${XDG_CONFIG_HOME:-\$HOME/.config}/sops/age/keys.txt).
+                     Ignored if \$SOPS_AGE_KEY is set (that always wins,
+                     same precedence sops/age itself uses).
+  --force            Overwrite <dest-path> if it already exists.
+  --dry-run          Print what would happen; write nothing.
+EOF
+}
+
+dry_run=0
+force=0
+key_file="$DEFAULT_SOPS_AGE_KEY_FILE"
+args=()
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --dry-run)
+      dry_run=1
+      shift
+      ;;
+    --force)
+      force=1
+      shift
+      ;;
+    --key-file)
+      key_file="${2:?--key-file requires a path}"
+      shift 2
+      ;;
+    -h | --help)
+      usage
+      exit 0
+      ;;
+    --*)
+      echo "Unknown option: $1" >&2
+      usage >&2
+      exit 1
+      ;;
+    *)
+      args+=("$1")
+      shift
+      ;;
+  esac
+done
+
+if [[ "${#args[@]}" -ne 1 ]]; then
+  usage >&2
+  exit 1
+fi
+dest="${args[0]}"
+
+nix_extra_opts
+
+if [[ -n "${SOPS_AGE_KEY:-}" ]]; then
+  echo "==> Source: \$SOPS_AGE_KEY (inline identity from the environment)."
+  src_content="$SOPS_AGE_KEY"
+else
+  [[ -s "$key_file" ]] || {
+    echo "ERROR: no key found. \$SOPS_AGE_KEY is unset and ${key_file} doesn't exist or is empty." >&2
+    exit 1
+  }
+  echo "==> Source: ${key_file}"
+  src_content="$(cat "$key_file")"
+fi
+
+# Round-trip through a private scratch file (rather than trusting the
+# source string as-is) so age-keygen -y validates it's a real identity
+# before anything is written to <dest-path>.
+scratch="$(mktemp)"
+trap 'rm -f "$scratch"' EXIT
+( umask 077; printf '%s\n' "$src_content" > "$scratch" )
+
+src_pub="$(age_pubkey_from_identity_file "$scratch")" || {
+  echo "ERROR: source doesn't look like a valid age identity (age-keygen -y failed)." >&2
+  exit 1
+}
+echo "    public key: ${src_pub}"
+
+current_admin_pub="$(sops_yaml_admin_pubkey "$sops_yaml")"
+if [[ -n "$current_admin_pub" && "$current_admin_pub" != "$src_pub" ]]; then
+  echo "NOTE: this key does not match .sops.yaml's current &admin entry (${current_admin_pub})."
+  echo "      Backing it up anyway -- this script doesn't require it to be the admin key."
+fi
+
+if [[ -e "$dest" && "$force" -ne 1 ]]; then
+  echo "ERROR: ${dest} already exists. Pass --force to overwrite." >&2
+  exit 1
+fi
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] would write $(wc -c <"$scratch" | tr -d ' ') bytes to ${dest} (mode 0600)"
+  [[ -e "$dest" ]] && echo "[dry-run] would overwrite existing file (--force given)"
+  echo "[dry-run] Nothing was written. Re-run without --dry-run to apply this."
+  exit 0
+fi
+
+mkdir -p "$(dirname "$dest")"
+install -m 600 "$scratch" "$dest"
+
+dest_pub="$(age_pubkey_from_identity_file "$dest")"
+if [[ "$dest_pub" != "$src_pub" ]]; then
+  echo "ERROR: ${dest} was written but its public key doesn't match the source -- investigate before relying on this backup." >&2
+  exit 1
+fi
+
+cat <<EOF
+
+Done. Backed up to: ${dest}
+  public key: ${dest_pub}
+
+This is a private key -- store it somewhere offline/secure, not in this
+repo or anywhere it'd get committed. Restore it with:
+  scripts/secrets/rotate-admin-key.sh ${dest}
+EOF
@@ -0,0 +1,83 @@
+#!/usr/bin/env bash
+# Generates a new machine's SSH host key by an arbitrary name, before it
+# necessarily has a flake target yet -- prints the .sops.yaml snippet to
+# add by hand. For any host that already has a flake target,
+# scripts/secrets/sync-host-keys.sh <target> does this same job plus the
+# .sops.yaml/key_groups registration and re-encryption automatically; use
+# this script only to pre-generate a key ahead of adding the flake target
+# itself.
+#
+# Why a host key is needed at all: sops-nix derives each host's decryption key from
+# its own /etc/ssh/ssh_host_ed25519_key at *activation* time, but that
+# activation runs before systemd would otherwise generate this key on
+# first boot (sshd-keygen is a normal systemd service gated behind
+# multi-user.target; activation scripts run earlier than that). Without
+# pre-seeding, secrets — including the root/nixos login password — fail
+# to decrypt on the machine's very first boot.
+#
+# This script only touches your admin workstation and this repo's
+# .sops.yaml (it never contacts the target machine). Run it, follow the
+# printed next steps, then use the resulting key with the auto-install.sh
+# prompt (see modules/installer/common.nix) when you actually install the
+# new machine.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=../lib/ssh-host-keys.sh
+source "${repo_root}/scripts/lib/ssh-host-keys.sh"
+
+hostname="${1:?usage: scripts/secrets/prepare-host-key.sh <hostname>}"
+sops_yaml="${repo_root}/.sops.yaml"
+
+if [[ ! -f "$sops_yaml" ]]; then
+  echo "ERROR: $sops_yaml not found — is this script still under nixos/scripts/?" >&2
+  exit 1
+fi
+
+keydir="${repo_root}/host-keys"
+mkdir -p "$keydir"
+keyfile="${keydir}/${hostname}_ssh_host_ed25519_key"
+
+if [[ -f "$keyfile" ]]; then
+  echo "ERROR: $keyfile already exists. Remove it first if you want to regenerate." >&2
+  exit 1
+fi
+
+nix_extra_opts
+generate_host_ed25519_key "$hostname" "$keyfile"
+
+age_pub="$(ssh_pubkey_to_age "${keyfile}.pub")"
+
+cat <<EOF
+
+Generated: ${keyfile}(.pub)
+
+=== 1. Add this line under keys: in ${sops_yaml} ===
+  - &${hostname} ${age_pub}
+
+=== 2. Add *${hostname} to whichever creation_rules key_groups this host needs ===
+(e.g. secrets/common.yaml always; add a per-host secrets/${hostname}.yaml
+ block too if this host will get its own secrets, same pattern as
+ nix-cache/server.)
+
+=== 3. Re-encrypt every secrets file you just added it to ===
+  nix-shell -p sops --run 'sops updatekeys ${repo_root}/secrets/common.yaml'
+
+=== 4. Commit + push this repo so the flake build picks up the new recipient ===
+
+=== 5. Get the key onto the installer, one of two ways ===
+  a) Rebuild the installer image with all host-keys/ baked in (see
+     docs/auto-installer.md):
+       NIXOS_HOST_KEYS_DIR="${keydir}" nix build .#iso --impure
+     (or .#pxe — --impure is required since host-keys/ is gitignored and
+     flakes can't see it otherwise)
+
+  b) Or, for an image already built without keys, scp it in after boot:
+       scp ${keyfile}{,.pub} root@<target-ip>:/root/host-keys/
+
+Then continue with /etc/auto-install.sh as normal — it checks
+/etc/host-keys (baked in) before /root/host-keys (scp'd) and installs
+whichever it finds before running nixos-install.
+EOF
@@ -0,0 +1,193 @@
+#!/usr/bin/env bash
+# Rotates the &admin sops age key: decrypts with a backed-up copy of the
+# key CURRENTLY trusted as &admin, replaces .sops.yaml's &admin entry with
+# a new key already present in this environment, and re-encrypts every
+# secrets/*.yaml for the new recipient set. After this runs, the old key
+# can no longer decrypt anything -- this is a real, one-way handoff of
+# trust, not a preview.
+#
+# This is the automation for the manual steps create-proxmox-resource.sh /
+# sync-host-keys.sh print when they bootstrap a brand-new, not-yet-trusted
+# age key on a machine that's never had admin access before:
+#
+#   scripts/secrets/rotate-admin-key.sh /path/to/backed-up/admin/keys.txt
+#
+# The backup key's *public* key must match .sops.yaml's current &admin
+# entry -- this script verifies that by deriving it, it doesn't just trust
+# the filename or take it on faith. The new key defaults to wherever sops
+# itself would already look ($SOPS_AGE_KEY_FILE, then the XDG default), so
+# the common case is just pointing this at the restored backup.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+sops_yaml="${repo_root}/.sops.yaml"
+
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=../lib/sops-age.sh
+source "${repo_root}/scripts/lib/sops-age.sh"
+
+# sops resolves .sops.yaml by walking up from the process's cwd, not from
+# the target file's own path -- if this script were invoked from somewhere
+# other than the repo root (or from inside another checkout/worktree that
+# happens to have its own .sops.yaml), `sops updatekeys` would silently
+# re-encrypt against the WRONG config's recipient list instead of this
+# repo's. Pin cwd here so every sops/age call below is unambiguous
+# regardless of where the caller's shell started out.
+cd "$repo_root"
+
+usage() {
+  cat <<EOF
+Usage: $0 <path-to-backed-up-admin-key> [--new-key-file <path>] [--dry-run]
+
+  <path-to-backed-up-admin-key>  age identity file for the key CURRENTLY
+                                 trusted as &admin. Only ever read -- never
+                                 copied or modified.
+  --new-key-file <path>          age identity file for the key to promote
+                                 to &admin. Defaults to \$SOPS_AGE_KEY_FILE,
+                                 then
+                                 \${XDG_CONFIG_HOME:-\$HOME/.config}/sops/age/keys.txt
+                                 (sops/age's own default resolution order).
+  --dry-run                      Print what would change; touches nothing
+                                  (.sops.yaml untouched, no sops updatekeys
+                                  calls).
+EOF
+}
+
+dry_run=0
+new_key_file="$DEFAULT_SOPS_AGE_KEY_FILE"
+args=()
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --dry-run)
+      dry_run=1
+      shift
+      ;;
+    --new-key-file)
+      new_key_file="${2:?--new-key-file requires a path}"
+      shift 2
+      ;;
+    -h | --help)
+      usage
+      exit 0
+      ;;
+    --*)
+      echo "Unknown option: $1" >&2
+      usage >&2
+      exit 1
+      ;;
+    *)
+      args+=("$1")
+      shift
+      ;;
+  esac
+done
+
+if [[ "${#args[@]}" -ne 1 ]]; then
+  usage >&2
+  exit 1
+fi
+backup_key="${args[0]}"
+
+[[ -s "$backup_key" ]] || { echo "ERROR: backup key file not found or empty: ${backup_key}" >&2; exit 1; }
+[[ -s "$new_key_file" ]] || { echo "ERROR: new key file not found or empty: ${new_key_file}" >&2; exit 1; }
+
+nix_extra_opts
+
+echo "==> Deriving public keys..."
+old_pub="$(age_pubkey_from_identity_file "$backup_key")"
+new_pub="$(age_pubkey_from_identity_file "$new_key_file")"
+echo "    backup (old admin) key: ${old_pub}"
+echo "    new admin key:          ${new_pub}"
+
+if [[ "$old_pub" == "$new_pub" ]]; then
+  echo "ERROR: backup key and new key are identical -- nothing to rotate." >&2
+  exit 1
+fi
+
+current_admin_pub="$(sops_yaml_admin_pubkey "$sops_yaml")"
+if [[ -z "$current_admin_pub" ]]; then
+  echo "ERROR: couldn't find a '&admin age1...' line in ${sops_yaml}." >&2
+  exit 1
+fi
+
+if [[ "$current_admin_pub" != "$old_pub" ]]; then
+  echo "ERROR: ${backup_key} doesn't match the current &admin key in .sops.yaml." >&2
+  echo "  .sops.yaml &admin: ${current_admin_pub}" >&2
+  echo "  backup key pubkey: ${old_pub}" >&2
+  echo "Wrong backup file, or .sops.yaml has already moved on -- not touching anything." >&2
+  exit 1
+fi
+
+mapfile -t secrets_files < <(find "${repo_root}/secrets" -maxdepth 1 -name '*.yaml' | sort)
+if [[ "${#secrets_files[@]}" -eq 0 ]]; then
+  echo "ERROR: no secrets/*.yaml files found under ${repo_root}/secrets." >&2
+  exit 1
+fi
+
+# sops_can_decrypt <key-file> <secrets-file>: used both to confirm the
+# backup key still works before touching anything, and again after
+# rotation to confirm the new key does too.
+sops_can_decrypt() {
+  local key_file="$1" secrets_file="$2"
+  SOPS_AGE_KEY_FILE="$key_file" nix-shell "${NIX_OPTS[@]}" -p sops --run \
+    "sops -d '${secrets_file}'" >/dev/null
+}
+
+echo "==> Confirming the backup key can actually decrypt..."
+if ! sops_can_decrypt "$backup_key" "${secrets_files[0]}"; then
+  echo "ERROR: backup key failed to decrypt $(basename "${secrets_files[0]}") -- aborting." >&2
+  exit 1
+fi
+echo "    OK: decrypted $(basename "${secrets_files[0]}")"
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] would replace .sops.yaml's &admin line:"
+  echo "[dry-run]   - ${current_admin_pub}"
+  echo "[dry-run]   + ${new_pub}"
+  echo "[dry-run] would then re-encrypt (sops updatekeys --yes) for the new recipient set:"
+  for f in "${secrets_files[@]}"; do
+    echo "[dry-run]   secrets/$(basename "$f")"
+  done
+  echo
+  echo "[dry-run] Nothing was changed. Re-run without --dry-run to apply this."
+  exit 0
+fi
+
+echo "==> Rotating .sops.yaml's &admin key..."
+sed -i "s|^  - &admin age1[a-z0-9]*|  - \&admin ${new_pub}|" "$sops_yaml"
+grep -qF "$new_pub" "$sops_yaml" || {
+  echo "ERROR: sed edit didn't take -- .sops.yaml left unchanged, check it by hand." >&2
+  exit 1
+}
+echo "    Updated."
+
+echo "==> Re-encrypting secrets/*.yaml for the new recipient set..."
+for f in "${secrets_files[@]}"; do
+  echo "==> $(basename "$f")"
+  sops_updatekeys "$f" "$backup_key"
+done
+
+echo "==> Verifying the new key can decrypt everything..."
+for f in "${secrets_files[@]}"; do
+  if ! sops_can_decrypt "$new_key_file" "$f"; then
+    echo "ERROR: new key failed to decrypt $(basename "$f") after rotation -- investigate before committing." >&2
+    exit 1
+  fi
+  echo "    OK: $(basename "$f")"
+done
+
+cat <<EOF
+
+Done. .sops.yaml's &admin key is now:
+  ${new_pub}
+
+The old key (${old_pub}) can no longer decrypt any secrets/*.yaml
+re-encrypted above.
+
+Review the diff, then commit:
+  git add .sops.yaml secrets/*.yaml
+  git commit -m "Rotate sops admin age key"
+EOF
@@ -0,0 +1,446 @@
+#!/usr/bin/env bash
+# Manages host-keys/ + .sops.yaml + secrets/*.yaml recipients together, so
+# a flake target's SSH host key and its sops registration never drift out
+# of sync with each other or with the flake itself.
+#
+#   sync-host-keys.sh --all                Generate/register every flake
+#                                           target missing a key.
+#   sync-host-keys.sh <target>              Same, for just one target.
+#   sync-host-keys.sh --remove              Interactively remove one
+#                                           locally-managed key.
+#   sync-host-keys.sh --regenerate-all-keys Remove and freshly regenerate
+#                                           every locally-managed key.
+#
+# "Generate/register" is idempotent and additive only: an existing
+# host-keys/ file is never touched, and .sops.yaml only ever gains an
+# anchor/alias it doesn't already have -- safe to re-run any time, e.g.
+# right after adding a new host to flake.nix.
+#
+# --remove and --regenerate-all-keys only ever operate on anchors that have
+# a corresponding host-keys/<name>_ssh_host_ed25519_key file. Anchors
+# without one (&admin, and any anchor for an already-deployed host whose
+# real /etc/ssh key was registered by hand, e.g. &docker/&server/&nix-cache
+# today) are never listed, removed, or regenerated -- this tooling only
+# ever touches keys it itself manages.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+sops_yaml="${repo_root}/.sops.yaml"
+keydir="${repo_root}/host-keys"
+editor="${repo_root}/scripts/lib/sync-host-keys-edit-sops.py"
+
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=../lib/nix-eval.sh
+source "${repo_root}/scripts/lib/nix-eval.sh"
+# shellcheck source=../lib/ssh-host-keys.sh
+source "${repo_root}/scripts/lib/ssh-host-keys.sh"
+# shellcheck source=../lib/sops-age.sh
+source "${repo_root}/scripts/lib/sops-age.sh"
+# shellcheck source=../lib/confirm.sh
+source "${repo_root}/scripts/lib/confirm.sh"
+
+mkdir -p "$keydir"
+
+usage() {
+  cat <<EOF
+Usage: $0 --all [--dry-run]
+       $0 <flake-target> [--dry-run]
+       $0 --remove [--dry-run]
+       $0 --regenerate-all-keys [--dry-run]
+
+  --all                    Generate + register a host key for every flake
+                            target that's missing one.
+  <flake-target>            Same, for just one target (e.g. lxc-server).
+                            Reports if it already has one.
+  --remove                  Interactively pick one locally-managed key to
+                            remove from .sops.yaml and host-keys/.
+  --regenerate-all-keys     Remove every locally-managed key and generate
+                            fresh replacements for every current flake
+                            target. Destructive -- requires typed
+                            confirmation.
+  --dry-run                 Combine with any of the above: print what would
+                            change (host-keys/ files, .sops.yaml anchors and
+                            key_groups, which secrets/*.yaml would be
+                            re-encrypted) without touching anything. No keys
+                            generated, no files written, no sops calls,
+                            no prompts for confirmation.
+EOF
+}
+
+# --- step 0: make sure we can actually decrypt anything at all -------------
+#
+# Registering a host means editing .sops.yaml and then running
+# `sops updatekeys`, which has to decrypt each secrets file with an
+# existing recipient's key before it can re-encrypt it for the new one.
+# Check this before doing anything else, the same order sops/age itself
+# resolves a usable key in: SOPS_AGE_KEY (inline), then SOPS_AGE_KEY_FILE,
+# then the XDG default path.
+ensure_admin_decrypt_key() {
+  if [[ -n "${SOPS_AGE_KEY:-}" ]]; then
+    echo "Using SOPS_AGE_KEY from the environment."
+    return
+  fi
+
+  local key_file="$DEFAULT_SOPS_AGE_KEY_FILE"
+
+  if [[ -s "$key_file" ]]; then
+    echo "Found existing sops age key at ${key_file}."
+    return
+  fi
+
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] No sops age decryption key found (checked \$SOPS_AGE_KEY, \$SOPS_AGE_KEY_FILE, ${key_file})."
+    echo "[dry-run] Would generate a new one here -- continuing the dry run without one; any"
+    echo "[dry-run] 'would re-encrypt' output below couldn't actually run for real yet."
+    return
+  fi
+
+  echo "No sops age decryption key found (checked \$SOPS_AGE_KEY, \$SOPS_AGE_KEY_FILE, ${key_file})."
+  echo "Generating a new one at ${key_file}..."
+  mkdir -p "$(dirname "$key_file")"
+  nix-shell "${NIX_OPTS[@]}" -p age --run "age-keygen -o '${key_file}'" 2>&1 | grep -v "^Public key:" || true
+  local new_pub
+  new_pub="$(age_pubkey_from_identity_file "$key_file")"
+
+  cat <<EOF
+
+A brand-new age key was just generated -- it cannot decrypt anything that
+already exists in secrets/*.yaml, since nothing was ever encrypted for it.
+That trust can't be bootstrapped automatically (nobody can decrypt a file
+for a recipient that didn't exist when it was last encrypted).
+
+To actually use this key:
+  1. Have someone who currently CAN decrypt replace the &admin entry in
+     .sops.yaml with this public key:
+       ${new_pub}
+  2. They re-encrypt every secrets/*.yaml:
+       sops updatekeys --yes secrets/common.yaml
+       sops updatekeys --yes secrets/nix-cache.yaml
+       sops updatekeys --yes secrets/server.yaml
+  3. Re-run this script.
+
+Exiting without making any other changes.
+EOF
+  exit 1
+}
+
+discover_targets() {
+  # installer is the one nixosConfigurations target that doesn't import
+  # sops-nix at all (see CLAUDE.md's "Security Notes" -- hardcoded login
+  # password instead) -- config.sops.secrets doesn't exist for it.
+  list_flake_targets "$repo_root" | grep -v '^installer$'
+}
+
+locally_managed_hosts() {
+  for f in "$keydir"/*_ssh_host_ed25519_key.pub; do
+    [[ -e "$f" ]] || continue
+    basename "$f" _ssh_host_ed25519_key.pub
+  done
+}
+
+add_keys_json="[]"
+add_aliases_json="[]"
+dry_run=0
+
+queue_host_sync() {
+  local host="$1"
+  local keyfile="${keydir}/${host}_ssh_host_ed25519_key"
+  local has_local_key=0 has_anchor=0
+  [[ -f "$keyfile" ]] && has_local_key=1
+  grep -qE "^  - &${host} age1" "$sops_yaml" && has_anchor=1
+
+  if [[ "$has_local_key" -eq 0 && "$has_anchor" -eq 1 ]]; then
+    echo "SKIP ${host}: .sops.yaml already has an &${host} anchor, but"
+    echo "     host-keys/${host}_ssh_host_ed25519_key is missing locally."
+    echo "     Not generating a replacement -- it wouldn't match whatever's"
+    echo "     already registered (and possibly deployed). Remove the"
+    echo "     &${host} line from .sops.yaml first if you really want a"
+    echo "     fresh key, then re-run."
+    return 1
+  fi
+
+  if [[ "$has_local_key" -eq 0 ]]; then
+    if [[ "$dry_run" -eq 1 ]]; then
+      echo "[dry-run] ${host}: would generate host key"
+    else
+      echo "==> ${host}: generating host key"
+      generate_host_ed25519_key "$host" "$keyfile"
+    fi
+  else
+    echo "==> ${host}: host key already present"
+  fi
+
+  if [[ "$has_anchor" -eq 0 ]]; then
+    local age_pub
+    if [[ "$dry_run" -eq 1 ]]; then
+      age_pub="dry-run-placeholder-not-a-real-key"
+    else
+      age_pub="$(ssh_pubkey_to_age "${keyfile}.pub")"
+    fi
+    add_keys_json="$(jq --arg host "$host" --arg key "$age_pub" \
+      '. + [{host: $host, age_key: $key}]' <<<"$add_keys_json")"
+  fi
+
+  echo "==> ${host}: checking which secrets files it references"
+  local basenames
+  mapfile -t basenames < <(
+    nix eval --json --no-use-registries --no-accept-flake-config \
+      "${repo_root}#nixosConfigurations.${host}.config.sops.secrets" \
+      --apply 'builtins.mapAttrs (n: v: baseNameOf v.sopsFile)' \
+    | jq -r '[.[]] | unique | .[]'
+  )
+  local basename
+  for basename in "${basenames[@]}"; do
+    add_aliases_json="$(jq --arg host "$host" --arg basename "$basename" \
+      '. + [{host: $host, basename: $basename}]' <<<"$add_aliases_json")"
+  done
+}
+
+# In dry-run, this runs the exact same edit logic (so idempotency/what's-
+# actually-new is determined for real, not guessed) but against a scratch
+# copy of .sops.yaml that's discarded afterward -- the real file is never
+# opened for writing, and `sops updatekeys` never runs.
+apply_edit_plan() {
+  local plan="$1"
+  local target="$sops_yaml"
+  local tmpfile=""
+  if [[ "$dry_run" -eq 1 ]]; then
+    tmpfile="$(mktemp)"
+    cp "$sops_yaml" "$tmpfile"
+    target="$tmpfile"
+  fi
+
+  local result
+  result="$(echo "$plan" | nix-shell "${NIX_OPTS[@]}" -p python3 --run "python3 '${editor}' '${target}'")"
+  [[ -n "$tmpfile" ]] && rm -f "$tmpfile"
+
+  local added removed changed
+  added="$(jq -r '.added_keys[]?' <<<"$result")"
+  removed="$(jq -r '.removed_keys[]?' <<<"$result")"
+  changed="$(jq -r '.changed_secrets_files[]?' <<<"$result")"
+
+  if [[ -z "$added" && -z "$removed" && -z "$changed" ]]; then
+    echo "Nothing changed in .sops.yaml."
+    return
+  fi
+
+  local prefix=""
+  [[ "$dry_run" -eq 1 ]] && prefix="[dry-run] would "
+
+  [[ -n "$added" ]] && echo "${prefix}Add .sops.yaml anchors: $(tr '\n' ' ' <<<"$added")"
+  [[ -n "$removed" ]] && echo "${prefix}Remove .sops.yaml anchors: $(tr '\n' ' ' <<<"$removed")"
+
+  if [[ -n "$changed" ]]; then
+    if [[ "$dry_run" -eq 1 ]]; then
+      echo "[dry-run] would re-encrypt:"
+      while IFS= read -r basename; do
+        [[ -z "$basename" ]] && continue
+        echo "  secrets/${basename}"
+      done <<<"$changed"
+    else
+      echo "Re-encrypting affected secrets files..."
+      while IFS= read -r basename; do
+        [[ -z "$basename" ]] && continue
+        echo "==> secrets/${basename}"
+        sops_updatekeys "${repo_root}/secrets/${basename}"
+      done <<<"$changed"
+    fi
+  fi
+}
+
+flush_additions() {
+  if [[ "$add_keys_json" == "[]" && "$add_aliases_json" == "[]" ]]; then
+    echo "Nothing to do -- every requested target already has a fully registered host key."
+    return
+  fi
+  echo
+  echo "Applying .sops.yaml edits..."
+  local plan
+  plan="$(jq -n --argjson add_keys "$add_keys_json" --argjson add_aliases "$add_aliases_json" \
+    '{add_keys: $add_keys, add_aliases: $add_aliases}')"
+  apply_edit_plan "$plan"
+  echo
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] Nothing was changed. Re-run without --dry-run to apply this."
+  else
+    echo "Done. Review the .sops.yaml / secrets/*.yaml diff, then commit and push --"
+    echo "the flake build the installer uses has to see the new recipient(s) before"
+    echo "any of these hosts can decrypt their secrets on first boot."
+  fi
+}
+
+cmd_all() {
+  echo "Discovering flake targets..."
+  local targets
+  mapfile -t targets < <(discover_targets)
+  local host
+  for host in "${targets[@]}"; do
+    queue_host_sync "$host" || true
+  done
+  flush_additions
+}
+
+cmd_target() {
+  local host="$1"
+  local targets
+  mapfile -t targets < <(discover_targets)
+  if ! printf '%s\n' "${targets[@]}" | grep -qxF "$host"; then
+    echo "ERROR: '${host}' is not a current nixosConfigurations target." >&2
+    echo "Current targets:" >&2
+    printf '  %s\n' "${targets[@]}" >&2
+    exit 1
+  fi
+  queue_host_sync "$host" || exit 1
+  flush_additions
+}
+
+cmd_remove() {
+  local hosts
+  mapfile -t hosts < <(locally_managed_hosts)
+  if [[ "${#hosts[@]}" -eq 0 ]]; then
+    echo "No locally-managed keys in host-keys/ -- nothing to remove."
+    return
+  fi
+
+  echo "Locally-managed keys:"
+  local i=1 host
+  for host in "${hosts[@]}"; do
+    local registered="not registered in .sops.yaml"
+    grep -qE "^  - &${host} age1" "$sops_yaml" && registered="registered in .sops.yaml"
+    printf '  %d) %s (%s)\n' "$i" "$host" "$registered"
+    i=$((i + 1))
+  done
+
+  local choice
+  read -rp "Remove which one? (number, or blank to cancel): " choice
+  if [[ -z "$choice" ]]; then
+    echo "Cancelled."
+    return
+  fi
+  if ! [[ "$choice" =~ ^[0-9]+$ ]] || (( choice < 1 || choice > ${#hosts[@]} )); then
+    echo "ERROR: invalid selection." >&2
+    exit 1
+  fi
+  local target="${hosts[$((choice - 1))]}"
+
+  if [[ "$dry_run" -ne 1 ]]; then
+    read -rp "Really remove '${target}'? Its host-keys/ files will be deleted and it will lose access to every secrets file it can currently decrypt. (y/N): " confirm
+    if [[ ! "$confirm" =~ ^[Yy]$ ]]; then
+      echo "Cancelled."
+      return
+    fi
+  fi
+
+  local plan
+  plan="$(jq -n --arg host "$target" \
+    '{remove_keys: [$host], remove_aliases_for_hosts: [$host]}')"
+  apply_edit_plan "$plan"
+
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] would delete host-keys/${target}_ssh_host_ed25519_key(.pub)."
+    echo "[dry-run] Nothing was changed. Re-run without --dry-run to apply this."
+  else
+    rm -f "${keydir}/${target}_ssh_host_ed25519_key" "${keydir}/${target}_ssh_host_ed25519_key.pub"
+    echo "Removed host-keys/${target}_ssh_host_ed25519_key(.pub)."
+    echo
+    echo "Review the diff, then commit and push."
+  fi
+}
+
+cmd_regenerate_all() {
+  local hosts
+  mapfile -t hosts < <(locally_managed_hosts)
+  if [[ "${#hosts[@]}" -eq 0 ]]; then
+    echo "No locally-managed keys in host-keys/ -- nothing to regenerate."
+    return
+  fi
+
+  echo "This will remove and freshly regenerate ALL locally-managed keys:"
+  printf '  %s\n' "${hosts[@]}"
+  echo
+  echo "Every host above will need its new key baked into a rebuilt install"
+  echo "image/tarball before it can decrypt secrets again."
+
+  if [[ "$dry_run" -ne 1 ]]; then
+    if ! confirm_typed "REGENERATE" "Type REGENERATE to confirm: "; then
+      echo "Cancelled."
+      return
+    fi
+  fi
+
+  echo
+  local hosts_json
+  hosts_json="$(printf '%s\n' "${hosts[@]}" | jq -R . | jq -s .)"
+  local plan
+  plan="$(jq -n --argjson hosts "$hosts_json" \
+    '{remove_keys: $hosts, remove_aliases_for_hosts: $hosts}')"
+  apply_edit_plan "$plan"
+
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] would delete ${#hosts[@]} host-keys/ file pair(s)."
+    echo "[dry-run] would then generate fresh replacements for the same hosts"
+    echo "[dry-run] (not simulated further here -- run without --dry-run, or"
+    echo "[dry-run] preview a specific target with: $0 <target> --dry-run)."
+    echo
+    echo "[dry-run] Nothing was changed. Re-run without --dry-run to apply this."
+    return
+  fi
+
+  echo "Removing existing keys..."
+  local host
+  for host in "${hosts[@]}"; do
+    rm -f "${keydir}/${host}_ssh_host_ed25519_key" "${keydir}/${host}_ssh_host_ed25519_key.pub"
+  done
+  echo "Removed ${#hosts[@]} host-keys/ file pair(s)."
+
+  echo
+  echo "Regenerating fresh keys for every current flake target..."
+  cmd_all
+}
+
+main() {
+  local args=()
+  local arg
+  for arg in "$@"; do
+    if [[ "$arg" == "--dry-run" ]]; then
+      dry_run=1
+    else
+      args+=("$arg")
+    fi
+  done
+  set -- "${args[@]+"${args[@]}"}"
+
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] no changes will be made"
+    echo
+  fi
+
+  nix_extra_opts
+  ensure_admin_decrypt_key
+
+  case "${1:-}" in
+    --all)
+      cmd_all
+      ;;
+    --remove)
+      cmd_remove
+      ;;
+    --regenerate-all-keys)
+      cmd_regenerate_all
+      ;;
+    -h | --help | "")
+      usage
+      ;;
+    --*)
+      echo "Unknown option: $1" >&2
+      usage >&2
+      exit 1
+      ;;
+    *)
+      cmd_target "$1"
+      ;;
+  esac
+}
+
+main "$@"
@@ -0,0 +1,110 @@
+#!/usr/bin/env bash
+# Detects and fixes drift between the ed25519 SSH host key nix-cache is
+# actually serving right now and vars.nixCacheHostKey (variables.nix) --
+# the value modules/nix-cache/remote-builder-client.nix bakes into every
+# client's declarative programs.ssh.knownHosts, and
+# scripts/proxmox/configure-nix-cache-client.sh hardcodes as its own
+# default for non-NixOS clients.
+#
+# This value has no automatic source of truth: nix-cache's host key is
+# generated once (first boot / container recreate) and never touches this
+# repo again unless someone remembers to update it by hand afterwards. It
+# drifted silently once already -- confirmed live: variables.nix recorded
+# a key that no longer matched what nix-cache actually presented, which
+# would fail every real client's SSH host-key verification for
+# distributed builds without ever producing an obvious error pointing
+# back here (a client just sees "Host key verification failed" against
+# *some* key, with no hint that the trusted value itself was stale).
+#
+# codex-maintenance.sh runs this in --check mode on every invocation so
+# that drift surfaces as a warning instead of a future debugging session.
+#
+# Usage:
+#   scripts/secrets/sync-nix-cache-host-key.sh [--check] [--dry-run] [--host <name>]
+#
+#   --check     Only report drift (exit 1 if found, 2 if nix-cache is
+#               unreachable); never writes. For CI/maintenance use.
+#   --dry-run   Show what would change; never writes.
+#   --host      Override the hostname to scan (default: variables.nix's
+#               nixCacheHost / env.sh's NIX_CACHE_HOST).
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+variables_nix="${repo_root}/variables.nix"
+client_script="${repo_root}/scripts/proxmox/configure-nix-cache-client.sh"
+
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+
+check_only=0
+dry_run=0
+host="${NIX_CACHE_HOST}"
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --check) check_only=1; shift ;;
+    --dry-run) dry_run=1; shift ;;
+    --host)
+      host="${2:?--host requires a hostname}"
+      shift 2
+      ;;
+    -h|--help)
+      sed -n '2,23p' "$0"
+      exit 0
+      ;;
+    *)
+      echo "ERROR: unknown argument: $1" >&2
+      exit 1
+      ;;
+  esac
+done
+
+current_value="$(grep -oE 'nixCacheHostKey = "[^"]+"' "$variables_nix" | sed -E 's/nixCacheHostKey = "(.*)"/\1/')"
+if [[ -z "$current_value" ]]; then
+  echo "ERROR: couldn't find nixCacheHostKey in $variables_nix" >&2
+  exit 1
+fi
+current_type_blob="$(awk '{print $1, $2}' <<<"$current_value")"
+current_label="$(awk '{print $3}' <<<"$current_value")"
+
+echo "Scanning ${host} for its current ed25519 SSH host key..."
+nix_extra_opts
+scanned="$(nix-shell "${NIX_OPTS[@]}" -p openssh --run "ssh-keyscan -t ed25519 -T 5 '${host}'" 2>/dev/null | grep -v '^#' | head -1 || true)"
+if [[ -z "$scanned" ]]; then
+  echo "ERROR: couldn't reach ${host} (or got no ed25519 host key back) via ssh-keyscan." >&2
+  exit 2
+fi
+scanned_type_blob="$(awk '{print $2, $3}' <<<"$scanned")"
+
+if [[ "$current_type_blob" == "$scanned_type_blob" ]]; then
+  echo "Up to date: ${host}'s host key matches variables.nix's nixCacheHostKey."
+  exit 0
+fi
+
+echo "DRIFT DETECTED:"
+echo "  variables.nix has: $current_type_blob"
+echo "  ${host} is now:    $scanned_type_blob"
+
+if [[ "$check_only" -eq 1 ]]; then
+  echo
+  echo "Run 'scripts/secrets/sync-nix-cache-host-key.sh' (no flags) to fix." >&2
+  exit 1
+fi
+
+new_value="${scanned_type_blob} ${current_label}"
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo "(--dry-run: would update variables.nix and ${client_script##*/} to:)"
+  echo "  $new_value"
+  exit 0
+fi
+
+sed -i "s|nixCacheHostKey = \"[^\"]*\"|nixCacheHostKey = \"${new_value}\"|" "$variables_nix"
+sed -i "s|NIX_CACHE_HOST_KEY:=[^}]*}|NIX_CACHE_HOST_KEY:=${new_value}}|" "$client_script"
+
+echo "Updated variables.nix and ${client_script##*/} to:"
+echo "  $new_value"
+echo
+echo "This only takes effect on already-deployed NixOS clients after their"
+echo "next rebuild (programs.ssh.knownHosts is declarative). Review with"
+echo "'git diff', then run 'bash scripts/codex-maintenance.sh' before committing."
@@ -5,40 +5,121 @@ sops:
    age:
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
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-            50f2fZ771ylhHa6WJMetGZ5cwl9r1RCaDiWyJEaqNGe7NqARlhr3EQ==
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+            djZTcE1rcWNTOXFPMmFDYTVoRGo4ZTQKYy8g6pqP3VpTKDIBPbnC8NzCdDvOCKnL
+            14kSrKmKlzefTrbkVyriz2Jdl2s0F374yfQQFreZ3m4AffSACCxziQ==
            -----END AGE ENCRYPTED FILE-----
-          recipient: age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+          recipient: age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBDamw2ekY0dFZyOGNJelVa
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-            o5vziOswRnuXENw//xN01nMDC6Ckzvb+q9GFIyxHLE4j3fT5XdZakg==
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+            BD09PI+T2DbIBQPotRZisw8IzHu9gY/O3+h0TccyIsXjI9wy/XPCAQ==
            -----END AGE ENCRYPTED FILE-----
          recipient: age19gfn2yedg76dmztm4hncr7vf3r3c9j0qpt4rap7y7gersjk4m3ks2lhd0e
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
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            -----END AGE ENCRYPTED FILE-----
          recipient: age1ll6hj5ggruetgjwjfnplpn5xtq35uhlcdflksx3xmnjm6s3uad9sz70jkf
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
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            -----END AGE ENCRYPTED FILE-----
          recipient: age120le4a5l8dh3lyfgvmj3d9ksmej6ajs5mer5y7r0vfg3x9fn69dqf8xgzu
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1jy444f9d9stygj4p3w9kh54cqcfr654tvr75tdvee5cxsgtdtc9q3v60ep
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age120whqj96g26lsgy4udvgsn8dc9lumh8jeu3a564fx79rjr5lxffqmrljuu
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1xjst4frdh0th6q8m7p7u9g5af7ty5jqeum0p6z8a52a9q7st7ewqw8yl9j
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age10at8862478urh0eeuwh8hzln6ck78jgwtztgxatwqlzwagg77y5snm4xzg
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1ezk9x53zt8kcnscdm80jcyf0xq97vndv7jsn3rl8cc0cwm2jmpmq372dzs
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1fxxzpnfse8nd9wz78ht3m0plrmraacf4cpga0pe8fm2tdnqcgy8q7qsyvp
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age190htw7prp4vln076dxjx3gxxaq06h0zl0te7cqgpx79vl3lhkaes8suy05
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1ukpqxzl44mnjpy5r96sfuc5sqzm47u4k8ujjh5qdgy6jvl9uqgpspymqfk
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age15kh7akxlx7zn00tey79rq2g8lgs4j5y77rcnyfxrxap8ckfu0a9sqvtdhh
    lastmodified: "2026-07-19T02:30:40Z"
    mac: ENC[AES256_GCM,data:UiL3VMDF6rq4Nr87KspcDx434q3tfNXeb5pwH2O+4ssNQ6xzcYDdzXBnhAY3zLBsqPMKrvHBd4Ot/gEMcq3FMIVe7Q6p9yWKpep66KZ/yWEhAlwIVhD79Oj8VS+1CHKjf25zpRdhZorp04oeFQQd9VfjJB4EE/Q1aVbwTGlpIic=,iv:i/0conaFgFia+wzNTdUL6tlSTw35HTK3Ap1Sr5RGHf8=,tag:ULbz5FllShA/JjlSRdxA0g==,type:str]
    unencrypted_suffix: _unencrypted
@@ -1,25 +1,35 @@
 beszel-token: ENC[AES256_GCM,data:meuzUP/6wCssJDVTgbC0XwiLZPMGyDl55HEIiON9xOXCD9k6,iv:TDqWcp+8Mxd8wN09r5otQRQXq3XTeQphaTWxvvuLTAs=,tag:cRPZQGlwB/dTguBAheWPQg==,type:str]
+cache-priv-key: ENC[AES256_GCM,data:6vQKIf7eS0WNL2Eptoi4VWr18SRMZfN/H/aFUUtXdMYQY5LLyBp2EHRKqZcGFuh1nZhUdAxUztq/CVXx+QFxKW+ElHxCxUSp0QqI1fdSkBkKZb8hlit5SoX9JtLzZGg0HBNM3nJu,iv:0J+xmrPJhInHhFR/c41ACjuTfaIoMkQFSfbL2KkgFa8=,tag:f4s9Szs5oprVVRSyXaX48A==,type:str]
 sops:
    age:
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
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            -----END AGE ENCRYPTED FILE-----
-          recipient: age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+          recipient: age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBCNWRhK2QrV1ZibllqY25Y
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            -----END AGE ENCRYPTED FILE-----
          recipient: age120le4a5l8dh3lyfgvmj3d9ksmej6ajs5mer5y7r0vfg3x9fn69dqf8xgzu
-    lastmodified: "2026-07-19T02:30:40Z"
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+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1xjst4frdh0th6q8m7p7u9g5af7ty5jqeum0p6z8a52a9q7st7ewqw8yl9j
+    lastmodified: "2026-07-19T23:30:21Z"
+    mac: ENC[AES256_GCM,data:kLGE2xawQT7mx+sfw68hmGk5nCEGiEjZrqTEl9B1dtQmTrMwmoVr/1RISi4LfJrwxy31mDgff4lcIL4wIJuM373uk3X8j4RNyYQNTfKEkORT6r8NHeepNs267O77pKGd7OmcM4MT/BqOnB8ELS7Wlf2ect7CAlvUUVyc8icxgZE=,iv:EYLDsHYHZ1XOQXafOTqHHWpk/OBNq/R6IJnOBYV33E4=,tag:thxrCPC5oGvDjhK7Dz87YA==,type:str]
    unencrypted_suffix: _unencrypted
    version: 3.13.1
@@ -3,22 +3,40 @@ sops:
    age:
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
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            -----END AGE ENCRYPTED FILE-----
-          recipient: age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+          recipient: age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
        - enc: |
            -----BEGIN AGE ENCRYPTED FILE-----
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            -----END AGE ENCRYPTED FILE-----
          recipient: age1ll6hj5ggruetgjwjfnplpn5xtq35uhlcdflksx3xmnjm6s3uad9sz70jkf
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1ukpqxzl44mnjpy5r96sfuc5sqzm47u4k8ujjh5qdgy6jvl9uqgpspymqfk
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
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+            -----END AGE ENCRYPTED FILE-----
+          recipient: age15kh7akxlx7zn00tey79rq2g8lgs4j5y77rcnyfxrxap8ckfu0a9sqvtdhh
    lastmodified: "2026-07-19T02:30:40Z"
    mac: ENC[AES256_GCM,data:rKHZjU/MH08ASTlu32HZO9uWmsBYuMCEC6M8gwVhzuWvmablnP05tS2z13XfaWaCEUXk6kmGJKuU0zu5+IKVZgamCF6DAMtxQb6bVCaLsoAm/GSqWQ5VI9eHqgnSSdN/o3ul/33Rf8iBQo4aw8FFAmDVuNz8bfAn0QefFTj0ByI=,iv:JD2gtqRinOY77etg6PUmZNovkYl1Q3F6ZvRi4x7RznQ=,tag:/5IMpWKRVt+l1luCTQE0BA==,type:str]
    unencrypted_suffix: _unencrypted
@@ -0,0 +1,168 @@
+{
+  # Network / domains
+  lanDomain = "gitea.lan.ddnsgeek.com"; # Gitea/DDNS domain
+  homeDomain = "sweet.home"; # base LAN domain for service subdomains (pve., docker.)
+  tailnetDomain = "tail13f623.ts.net"; # Tailscale MagicDNS suffix
+  lanCidr = "192.168.2.0/24"; # LAN subnet
+  pxeServerIp = "192.168.2.247"; # pxe-boot host's LAN IP
+  pbsIp = "192.168.2.108"; # Proxmox Backup Server LAN IP
+
+  # Cross-host references (LAN hostnames/users other hosts reach over the network)
+  nixCacheHost = "nix-cache"; # substituter/remote-builder hostname
+  nfsServerHost = "server"; # NFS export source hostname
+  dockerHost = "docker"; # docker-compose stack host
+
+  # Raspberry Pi's own Tailscale hostname (not fronted by `server` — it
+  # exports its own NFS share directly). Resolved as
+  # "${raspberryPiHost}.${tailnetDomain}" in modules/raspi/mount-data.nix.
+  raspberryPiHost = "raspberrypi";
+
+  remoteBuilderUser = "nixremote"; # remote builder SSH user
+
+  # nix-cache's own SSH host public key (not a secret — the private half
+  # never leaves the host). Wired into every client's
+  # programs.ssh.knownHosts by modules/nix-cache/remote-builder-client.nix
+  # so distributed builds don't hit "Host key verification failed" on a
+  # fresh client that has never manually ssh'd to nix-cache before. Update
+  # this if nix-cache's host key is ever rotated or the host is rebuilt
+  # from scratch.
+  nixCacheHostKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPeWgMsdaiz4axT/deFc1+0B5bN+GX/NOeW9bbQ0c/IT lxc-nix-cache";
+
+  # Public keys authorized to SSH in as remoteBuilderUser on the nix-cache
+  # host (modules/nix-cache/server.nix) — one per client host that's allowed
+  # to use it as a distributed builder.
+  remoteBuilderAuthorizedKeys = [
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFDEA1S2ikpObREgbP5uVBWMxIOGbY8B+Wx7VTZK1m6t root@server"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPAYIT9ormlmxZ0SziyDQaUntnKI8HK9/s3Qac1ZKjP2 root@docker"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKKKzoEPl/ZW9KBRHBcp6/ThOngGpwMv5EhkTlgC4aDf root@nixos"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIGtOWOCS+ImHc7NehguoyD7PbonGosKMZqc9+QR3v/h root@nixos"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHxXTQxFnArK5HXG7czeoybZebCGfxpUdusJkPn+BCSp root@server"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICMJhrfFayLBG+gWtO6oAvgambw5nWWgztiTFEaaaVRH debian@surface"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJEj26SL/emsVjW2YhRucJVp2kTz8WgcEQgjBEBLRikk root@claude"
+  ];
+
+  # Admin SSH public key, authorized on the primary user of every host and
+  # the installer image's nixos/root users.
+  adminSshKey = "ssh-rsa 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 wayne@stream";
+
+  # System
+  timeZone = "Australia/Brisbane";
+
+  # Main interactive user on every host. Every module that grants this user
+  # a group, a home directory, or tmpfiles ownership should reference
+  # vars.primaryUser rather than the literal "nixos", so renaming it is a
+  # one-line change.
+  primaryUser = "nixos";
+
+  # Storage
+  storageRoot = "/tank"; # ZFS pool root on `server`
+
+  # NFS datasets exported from `storageRoot` on `nfsServerHost` and mounted
+  # by client hosts. `subpath` is relative to `storageRoot` — combined with
+  # it to build both the export line in modules/build-types/server.nix and
+  # the "<nfsServerHost>:<storageRoot>/<subpath>" device string each client
+  # mount uses in modules/docker/mount-data.nix. `mountpoint` is the
+  # absolute local path clients mount it at, referenced by that same file's
+  # fileSystems attribute name plus every other place that needs to know
+  # where the share lives locally (modules/build-types/docker.nix's
+  # tmpfiles rules, modules/traefik/rotate-logs.nix's log path). Renaming a
+  # dataset or moving where it's mounted only needs changing it here — the
+  # export and every client reference follow automatically.
+  nfsShares = {
+    dockerConfig = {
+      subpath = "docker/config";
+      mountpoint = "/mnt/docker/config";
+    };
+    dockerDatabases = {
+      subpath = "docker/databases";
+      mountpoint = "/mnt/docker/databases";
+    };
+    dockerVolumes = {
+      subpath = "docker/volumes";
+      mountpoint = "/mnt/docker/volumes";
+    };
+    nextcloudData = {
+      subpath = "docker/nextcloud-data";
+      mountpoint = "/mnt/nextcloud-data";
+    };
+    raspiVolumes = {
+      subpath = "raspi/volumes";
+      mountpoint = "/mnt/raspi-backup";
+    };
+  };
+
+  # The Raspberry Pi's own NFS export — not under storageRoot/nfsServerHost,
+  # served directly by the Pi itself over Tailscale (see raspberryPiHost
+  # above) and mounted at raspiMountpoint by modules/raspi/mount-data.nix.
+  raspiNfsPath = "/home/raspi/raspi";
+  raspiMountpoint = "/mnt/raspi";
+
+  # Every literal port referenced from modules/ or hosts/, grouped by the
+  # service/host that opens or connects to it — kept as separate entries
+  # even where two happen to share a number today (e.g. nixCacheHttp and
+  # pxeBootHttp are both 80) so changing one service's port can never
+  # silently change an unrelated one.
+  ports = {
+    # nix-cache's nginx reverse proxy in front of nix-serve
+    # (modules/nix-cache/server.nix).
+    nixCacheHttp = 80;
+
+    # pxe-boot's nginx asset server, also used to build pxeBaseUrl
+    # (modules/build-types/pxe-boot.nix).
+    pxeBootHttp = 80;
+
+    # pxe-boot's atftpd TFTP server — UDP, not TCP
+    # (modules/build-types/pxe-boot.nix).
+    pxeBootTftp = 69;
+
+    # `server`'s NFS exports need both the portmapper (rpcbind) and the
+    # NFS data port itself opened (modules/build-types/server.nix).
+    nfsRpcbind = 111;
+    nfsd = 2049;
+
+    # Opened on the docker host's firewall for the Traefik-fronted
+    # container stack (docker-compose config lives in the separate
+    # /home/debian/docker repo, not here): 80/443 are Traefik's own
+    # HTTP/HTTPS listeners; 8080 is an additional exposed service whose
+    # exact backend isn't declared in this repo (modules/build-types/docker.nix).
+    dockerHttp = 80;
+    dockerHttps = 443;
+    dockerExtra = 8080;
+
+    # Beszel monitoring hub, reachable at
+    # http://<dockerHost>.<homeDomain>:<beszelHub> from every agent
+    # (modules/beszel/enable-agent.nix, hosts/nixos/home.nix).
+    beszelHub = 8090;
+
+    # Proxmox VE and Proxmox Backup Server web UIs, opened as desktop
+    # shortcuts on the gui build type (hosts/nixos/home.nix).
+    pveWeb = 8006;
+    pbsWeb = 8007;
+
+    # Tor relay's ORPort — the port other Tor relays connect to for onion
+    # routing traffic (modules/tor/enable-relay.nix). Tor's own conventional
+    # default; opened via services.tor.openFirewall rather than
+    # networking.firewall.allowedTCPPorts directly, but kept here anyway so
+    # it's not a bare literal duplicated between the relay's settings and
+    # anything else that ever needs to reference it.
+    torRelayOrPort = 9001;
+  };
+
+  # .raw disk image size for every proxmox-* host's standalone Disko image
+  # build (modules/disko/proxmox.nix, config.system.build.diskoImagesScript
+  # — see docs/proxmox-images.md). Root fills whatever's left after the ESP
+  # and swap partitions within this total.
+  proxmoxImageSize = "20G";
+
+  # nix-cache's Nix store garbage collection retention
+  # (modules/nix-cache/server.nix).
+  nixCacheGcMaxAge = "30d";
+
+  # Traefik access log rotation, watched on the docker host at
+  # nfsShares.dockerVolumes.mountpoint (modules/traefik/rotate-logs.nix).
+  traefikLogRotate = {
+    maxSize = "100M"; # rotate once a log file exceeds this size
+    keep = 20; # number of rotated logs to retain before deleting the oldest
+  };
+
+}