feat: decommission server.sweet.home

Removes all flake artifacts for the retired NFS/ZFS file server:
- flake.nix: drop linode-server, proxmox-server, lxc-server targets
- hosts/server/: delete host identity
- modules/build-types/server.nix: delete build type (ZFS pool + NFS exports)
- vars/per-machine/{linode,lxc,proxmox}-server/: delete clan vars
- secrets/server.keytab: delete IPA keytab
- .sops.yaml: remove server key anchors, strip from common.yaml recipients,
  delete server.yaml and server.keytab creation rules
- variables.nix: remove serverIp, serverStorageIp (nfsServerHost/storageRoot
  retained — pxe-boot/mount-pxe-images.nix still references them)
- docs: mark server decommissioned in ip-addressing.md

Docker NFS mounts already pointed at nfs.storage.home (previous commit).
VM destruction and DNS cleanup (server.sweet.home, server.storage.home
A/PTR records) to follow once the VM is confirmed stopped.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J8djTWdXVzXZc99iujU6T2

modules/build-types/server.nix

@@ -1,121 +0,0 @@
-{ vars, lib, pkgs, ... }:
-
-let
-  poolName = lib.removePrefix "/" vars.storageRoot;
-
-  # For each NFS share subpath, generate every ancestor path so ZFS datasets
-  # are created parent-first.  e.g. "docker/config" → ["docker" "docker/config"]
-  ancestors = path:
-    let parts = lib.splitString "/" path;
-    in lib.imap1 (i: _: lib.concatStringsSep "/" (lib.take i parts)) parts;
-
-  poolDatasets = lib.unique (
-    lib.concatMap (share: ancestors share.subpath)
-      (lib.filter builtins.isAttrs (lib.attrValues vars.nfsShares))
-  );
-
-  # Generates /etc/exports lines for all nfsShares data entries (every
-  # attrset value — excludes the bare `options` string). Both server and
-  # ha-server export the same share set from different storage roots, so
-  # this helper is the single source of truth for the export line format.
-  mkNfsExports = storageRoot:
-    lib.concatMapStrings
-      (share: "  ${storageRoot}/${share.subpath} ${vars.lanCidr}${vars.nfsShares.options}\n")
-      (lib.filter builtins.isAttrs (lib.attrValues vars.nfsShares));
-in
-{
-  imports = [
-    ../beszel/enable-agent.nix
-    ../services/zfs/enable-service.nix
-  ];
-
-  boot.zfs.extraPools = [ poolName ];
-
-  # On a fresh image deploy the data disk (scsi1) starts blank — no pool
-  # exists yet, so zfs-import-tank.service would spin for 60 s and fail.
-  # This service runs first: if the pool is already present it exits instantly;
-  # otherwise it creates it (with all required datasets) so the standard
-  # import service finds it ready on the very first boot.
-  systemd.services."zfs-init-${poolName}" = {
-    description = "Initialize '${poolName}' ZFS pool on first boot if not present";
-    wantedBy = [ "zfs-import-${poolName}.service" ];
-    before = [ "zfs-import-${poolName}.service" ];
-    after = [ "systemd-udev-settle.service" ];
-    unitConfig.DefaultDependencies = false;
-    serviceConfig = {
-      Type = "oneshot";
-      RemainAfterExit = true;
-    };
-    path = [ pkgs.zfs_unstable ];
-    script = ''
-      # Already imported — nothing to do.
-      if zpool list "${poolName}" >/dev/null 2>&1; then
-        exit 0
-      fi
-
-      # Locate the data disk first — used for both the fallback import
-      # attempt and, only if the disk is genuinely blank, pool creation.
-      DATA_DISK=""
-      for candidate in /dev/disk/by-id/scsi-*drive-scsi1; do
-        [[ "$candidate" == *-part* ]] && continue
-        [ -b "$candidate" ] && DATA_DISK="$candidate" && break
-      done
-
-      if [ -z "$DATA_DISK" ]; then
-        echo "zfs-init-${poolName}: no data disk found (expected /dev/disk/by-id/scsi-*drive-scsi1)" >&2
-        exit 1
-      fi
-
-      # Try importing via the by-id symlink directory first (normal path),
-      # then fall back to scanning the disk directly.  The two-step exists
-      # because of a udev race: systemd-udev-settle.service can clear before
-      # /dev/disk/by-id/ entries are fully populated, causing the first
-      # import to fail even when the pool is intact on the disk.
-      if zpool import -d /dev/disk/by-id -N "${poolName}" 2>/dev/null; then
-        exit 0
-      fi
-      if zpool import -d "$DATA_DISK" -N "${poolName}" 2>/dev/null; then
-        exit 0
-      fi
-
-      # Both import attempts failed.  Before creating a new pool, verify the
-      # disk is genuinely blank — if ZFS label metadata is present the import
-      # failed for some other reason and we must not clobber existing data.
-      if zdb -l "$DATA_DISK" 2>/dev/null | grep -q "name: '${poolName}'"; then
-        echo "zfs-init-${poolName}: $DATA_DISK has ZFS pool '${poolName}' metadata but import failed — refusing to overwrite existing data. Run 'zpool import -d $DATA_DISK ${poolName}' manually to investigate." >&2
-        exit 1
-      fi
-
-      # Disk is genuinely blank: create the pool.  -f is intentionally
-      # omitted so that if we somehow reach this point with an existing pool
-      # on the disk, zpool refuses rather than silently destroying data.
-      echo "zfs-init-${poolName}: creating pool on $DATA_DISK"
-      zpool create "${poolName}" "$DATA_DISK"
-      ${lib.concatMapStrings (ds: ''
-        zfs create "${poolName}/${ds}"
-      '') poolDatasets}
-    '';
-  };
-
-  systemd.services.nfs-server = {
-    after = [ "zfs-mount.service" ];
-    requires = [ "zfs-mount.service" ];
-  };
-
-  # rpc-svcgssd handles Kerberos/GSS-API for NFS. Not needed: exports use
-  # standard auth, not sec=krb5. On IPA-joined hosts the keytab exists (host/
-  # principal only) but has no nfs/ principal, causing spurious failure.
-  # Mask it so nfs-server's Wants= can't pull it in.
-  systemd.services.rpc-svcgssd.enable = false;
-
-  services.nfs.server = {
-    enable = true;
-    exports = mkNfsExports vars.storageRoot;
-  };
-
-  # mountd (20048) is needed for showmount/NFSv3 mount protocol — without it
-  # clients can reach portmapper (111) and get the mountd port back, then
-  # time out trying to connect to it. All three ports need TCP and UDP.
-  networking.firewall.allowedTCPPorts = [ vars.ports.nfsRpcbind vars.ports.nfsd vars.ports.nfsMountd ];
-  networking.firewall.allowedUDPPorts = [ vars.ports.nfsRpcbind vars.ports.nfsd vars.ports.nfsMountd ];
-}