Add ADR-029/030, implementation tasks, and spec updates for admin socket removal

Security review #005 identified critical vulnerabilities in the Unix domain
socket admin API (C1 symlink race, C2 no auth, C3 info leak, W1-W7, S1-S6).
ADR-028 (already accepted) replaces the socket with an authenticated HTTP
admin API on the health check port. This commit adds the remaining spec work:

- ADR-029: Config file TOCTOU mitigation (mtime check on reload)
- ADR-030: Store cli_allow_wildcard_bind in ConfigReloadHandle for consistent
  reload validation
- Implementation tasks for the admin HTTP migration (fix/admin-http-api),
  TOCTOU fix (fix/config-reload-toctou), and wildcard flag fix
  (fix/wildcard-flag-reload)
- Updated review #005 status to resolved with per-finding disposition
- Resolved OQ-16: POST for state-changing admin endpoints, GET for read-only
- Updated all architecture docs to reference new ADRs, use admin_key_path
  instead of admin_socket_path, and reflect POST method for /admin/reload

docs/architecture/decisions/013-health-check-port.md

@@ -48,8 +48,8 @@ listener (see ADR-022).
 - Configurable port allows different deployment scenarios (some monitoring runs
   on different ports)
 - Disabling via `health_check_port = 0` removes the health check entirely —
-  the admin socket's `status` command remains available as an alternative
-  health/status mechanism
+   the admin HTTP endpoint's `/admin/status` (with Bearer token) remains available
+   as an alternative health/status mechanism (ADR-028)
 - When this project is folded into alknet, the health check will use alknet's
   existing patterns, making the separate port unnecessary in that context
 
@@ -69,4 +69,5 @@ listener (see ADR-022).
 
 - [operations.md](../operations.md)
 - [ADR-022](022-health-check-scope.md) — Health check scope (no `/health` on main listener)
+- [ADR-028](028-admin-http-api.md) — Authenticated HTTP admin API (admin endpoints on health check port)
 - OQ-03 (now resolved)