- Replace direct better-sqlite3 imports with DatabaseAdapter pattern
- Make all muxer-queue functions async to support both SQLite and PostgreSQL
- Update database initialization to use adapter's getDatabase()
- Export DatabaseAdapter as SqliteDatabase for backward compatibility
- Update index.ts to handle async database initialization
- Update webserver.ts to await async database operations
- All functions now work with both SQLite and PostgreSQL backends
- Tests pass, no TypeScript errors
