Add level-up announcements, new plugins, scheduler overhaul, and bug fixes

- Level-up announcements with Twinbee/Parodius-themed messages and emoji flair
- New plugins: !howami (LLM stat roast), !vibe (room energy), !tldr (conversation summary)
- !game command as primary game lookup with !retro as alias
- Prefetch system: API data cached at 00:05 UTC for reliable scheduled posts
- Nightly maintenance job: prunes old data across 15+ tables
- Sentiment aggregation: new sentiment_stats table with backfill migration
- Access token moved from .env to device.json for security
- Retry logic (sendReact/sendWithRetry) for transient connection failures
- Trivia crash fix: optional chaining on threadEventId across all locations
- Bug fixes: COALESCE for NULL SUM in howami, unused params in vibe, dead try-catch in fun
- License updated from ISC to MIT
- README: weather section expanded, prefetch/maintenance documented

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -2,6 +2,7 @@
   "name": "freebee",
   "version": "1.0.0",
   "description": "A full-featured Matrix community bot with E2EE support, plugin architecture, and community engagement features",
+  "license": "MIT",
   "main": "dist/index.js",
   "scripts": {
     "build": "tsc",