Add pve.sweet.home guard rails to CLAUDE.md

Codifies read-only access to existing Proxmox config/VMs/containers,
allows scratch test VMs/containers as long as they're torn down again,
and forbids any change to production on the node.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CLAUDE.md

@@ -31,6 +31,33 @@ machines when deployed.
   the auto-installer (see `docs/auto-installer.md`). Never commit its
   contents; if `git status` ever shows it as trackable, something is wrong.
 
+### `pve.sweet.home` (the Proxmox node)
+
+`pve.sweet.home` (`PROXMOX_HOST` in `scripts/env.sh`) is a real, live Proxmox
+node hosting production VMs/containers — not a sandbox.
+
+- **Read-only for existing state.** 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, or reconfigure anything that already exists there (`qm set`,
+  `pct set`, `qm destroy`, `pct destroy`, `qm stop`, `pct stop`, snapshot
+  operations, storage changes, etc.) without the operator's explicit
+  go-ahead.
+- **Test VMs/containers are allowed, but must be torn down.** You may create
+  a scratch VM or container on the node (e.g. via
+  `scripts/proxmox/create-proxmox-resource.sh` or raw `qm`/`pct create`) to
+  validate something. Anything you create this way must be destroyed again
+  in the same session, before ending the task — never leave a test
+  resource running on the node. 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.
+- **No changes to production, ever, from an agent session** — this covers
+  both the node itself (Proxmox host config, storage pools, networking) and
+  any pre-existing guest. Anything beyond inspecting and tearing down your
+  own scratch resources is the operator's call to make manually, same as
+  the deploy commands above.
+
 ## Commands
 
 ```bash