Add reversible administrator room archiving

Organize closed rooms with archive filters, live-authorized atomic receipts and exact saved retries. Preserve saved games, timestamps, credentials, discussion and AI deadlines. Unarchive leaves play closed; reopen requires unarchive, and removal/restoration preserves both flags.

Verified types, lint, 5379 offline tests, 52 HTTP tests and build. Twenty dedicated administrator HTTP groups and independent privacy/persistence review passed. Desktop/mobile browser QA confirmed a single archive after a lost response and refresh, readable recovery text, mobile unarchive and separate reopening, and saved-seat restoration. All 2,049 baseline rooms, 4,348 seats and related records preserved. Authenticated production admin acceptance awaits authorized QA access; full admin and rules gates remain open.

docs/IMPLEMENTATION_STATUS.md

@@ -1,5 +1,21 @@
 # Dune implementation status
 
+## 22 September 2026 — Administrative archive/unarchive prototype
+
+[Archive or unarchive](ADMIN_ROOM_ARCHIVE.md) organizes closed rooms without
+changing their saved state, timestamps, credentials, discussion or AI pacing.
+Separate directory filters compose with removal; unarchive leaves play closed,
+reopen rejects archives, and removal/restoration retains both flags. Live
+operator authority and room/archive version fences commit with durable audit
+receipts. Tab-scoped exact retries remain confirmable across refresh and later
+availability changes.
+
+Independent read-only review found no material issues. Focused database/client
+checks and twenty dedicated administrator HTTP groups passed. Browser acceptance,
+source-bound broad checks and preservation evidence accompany the checkpoint.
+Authenticated production acceptance awaits authorized QA access. Full admin and
+rules gates remain unfinished.
+
 ## 22 September 2026 — Administrative close/reopen prototype
 
 [Close or reopen](ADMIN_ROOM_CLOSURE.md) now separates administrative availability