feat(trust): pin release-root anchor + ship signed app-catalog

Pin RELEASE_ROOT_PUBKEY_HEX from the 2026-07-02 release-root signing ceremony
(signer did:key:z6MkkidEnEpo6qHMCNSZoNKWtvQvxq3whnaME9wGgEFhq7ur) so nodes verify
the publisher identity of the app-catalog. Sign releases/app-catalog.json in place.

Fix two floats that made the catalog unsignable: archy-btcpay-db manifest version
-> string, fedimint-clientd cpu_limit 0.25 -> 1 (u32). Add scripts/sign-catalog.sh
helper, the 1.8.0 release-hardening plan/tracker, and the commit-and-push project
rule in CLAUDE.md.

Backward-compatible: old binaries still accept the signed catalog; the pinned-anchor
binary ships in the next build/OTA.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CLAUDE.md

@@ -26,6 +26,28 @@ Detailed sub-plans (all linked from the master):
 - Current per-app state → `docs/app-registry-status-2026-06-21.md`
 - Production test gate (exit criterion) → `tests/lifecycle/TESTING.md`
 
+## Commit & push every unit of work (never violate)
+
+**The #1 process rule: work is not "done" until it is committed AND pushed.** This
+exists because finished work has been lost/clobbered by sitting uncommitted in the
+shared tree across agents and sessions. To prevent that:
+
+- **Commit each feature/fix the moment it works** — one focused, self-contained
+  commit per logical change (it compiles and its targeted tests pass). Do not let
+  unrelated changes accumulate uncommitted.
+- **Push immediately after committing** so nothing lives only on one machine. `main`
+  is protected → push via `git push gitea-ai main` (account `ai`, see the memory
+  note); feature branches push to their own remote.
+- **Never leave a stack of finished work uncommitted** overnight or when handing off
+  between agents — if you must pause mid-change, commit a clearly-labelled WIP
+  checkpoint rather than leaving it dirty.
+- **Stage explicitly by path** (`git add <paths>`) when another agent's uncommitted
+  work shares the tree — never `git add -A` / `git commit -a`, which clobbers or
+  entangles their changes.
+- **Never commit or push secrets** (mnemonics, private keys, API tokens). Signing is
+  done offline; artifacts (catalog/manifest) are signed, not the keys.
+- Commit messages end with the `Co-Authored-By: Claude …` trailer.
+
 ## Invariants (never violate)
 
 - **Rootless Podman only.** No rootful, no Docker-socket mounts, no privileged