Add administrative room close and reopen controls

Preserve readable private tables, discussion and pending games while closure blocks new play, joins, messages, AI and seat mutations. Add live-authorized atomic closure audits, room-version/revision fences, dedicated controls and exact saved retries. Reopen with the saved pause/join settings and current credentials; restoring a removed but closed room keeps its AI stopped.

Verified types, lint, 5356 offline tests, 52 HTTP tests and build. Seventeen dedicated authenticated HTTP groups and independent privacy/persistence review passed. Desktop/mobile browser QA confirmed one close after a lost response and refresh, persistent readable notices, retained private draft, mobile reopening and saved-seat refresh. All 2,001 baseline rooms, 4,243 seats and related records preserved. Positive production admin acceptance awaits authorized QA access; full admin and rules gates remain open.

tests/seat-recovery-render.test.tsx

@@ -0,0 +1,11 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { renderToStaticMarkup } from 'react-dom/server';
+import { SeatRecoveryClaim } from '../components/seat-recovery';
+
+void test('saved-seat recovery renders without a browser window or ambient closed variable', () => {
+  assert.equal('closed' in globalThis, false);
+  const html = renderToStaticMarkup(<SeatRecoveryClaim onRestored={() => {}} />);
+  assert.match(html, /Recover a saved seat/);
+  assert.match(html, /Paste your private recovery kit/);
+});