docs: felhom-agent CLAUDE.md becomes a core plus path-scoped rules (R-229 leg b)

175 -> 99 effective lines. New .claude/rules/{proxmox,localapi,backup,storage}.md alongside the
existing health-checks.md. The release section points at the felhom-build-deploy skill rather than
restating a table that drifts from the script; the layout section's per-package annotations moved
into the rule file for their area instead of being deleted.

Kept in the core because it is the only part re-injected after /compact: the root-CLI fence and its
three exceptions, the destructive-op gate, prove-ownership (audit A1), the gate entry point, the F9
live-validation fence, and the checklist.

health-checks.md overlaps localapi.md and storage.md on three globs -- deliberate, both load,
stated in each file. Go build/vet/test green and unchanged.

.claude/rules/localapi.md

@@ -0,0 +1,44 @@
+---
+paths: ["internal/localapi/**", "internal/authz/**", "internal/guesthook/**"]
+---
+
+# Local API, authz and guest hooks — the per-guest blast radius
+
+`internal/localapi/` is the narrow per-guest local API: token store, disks/format, guest binds,
+controller swap, stale-lock recovery, pinned self-signed leaf. `internal/authz/` is the operator
+signed-op verifier (SSHSIG) plus the durable nonce store. `internal/guesthook/` installs the
+pre-start self-heal hookscript.
+
+> **Overlap note:** `health-checks.md` also matches `internal/localapi/**` and
+> `internal/guesthook/**`. That is deliberate — both rules apply there and both load. Neither
+> supersedes the other.
+
+## Scoping is the whole security property
+
+This API is reachable **from inside a customer guest**. Every route must be scoped to the guest that
+called it — a route that can name another guest's id has escaped its blast radius. Fail **safe to
+protected**: an unrecognised or unresolvable caller gets less access, never more.
+
+## Replay protection must survive a restart
+
+**`authz.MemoryNonceStore` on a real host is a defect** — replay protection dies on restart. Use
+`authz.FileNonceStore`. The memory store exists for tests.
+
+## The token is a hash on disk, plaintext only at mint
+
+The store keeps **hashes**. The plaintext token exists in exactly one place, `bootstrap.json` on the
+PVE host — so a "read the token" step means reading that file, and a lost token is re-minted, never
+recovered.
+
+## Binds can brick guest boot
+
+| Do not | Because | Use |
+|---|---|---|
+| `GuestBinder.AttachBind`/`DetachBind` (per-drive `pct set -mpN`) | legacy model; a missing bind source can **brick guest boot** (C1) | `AttachDrive`/`DetachDrive` (intermediary model) |
+| `isHostMountpoint` to reconcile bind state | a boolean cannot converge stacked double-binds (the `/mnt` doubling bug) | `countHostMounts` normalization inside `AttachDrive` |
+
+<!--
+Why fail-safe-to-protected rather than fail-closed: this API also carries the recovery paths. A hard
+refusal on an unresolvable caller would make a half-broken guest unrecoverable through the very
+interface built to recover it. Less access, never none.
+-->