feat: Implement session management and search functionality

- Added SDK session, observation, and summary types to types.ts.
- Refactored worker-service to use SessionStore for session management.
- Created SessionSearch class for FTS5 full-text search and structured queries.
- Implemented SessionStore for CRUD operations on SDK sessions, observations, and summaries.
- Added migrations for database schema updates, including new columns and constraints.
- Enhanced search capabilities with filters for projects, types, concepts, and date ranges.

src/services/sqlite/index.ts

@@ -1,8 +1,11 @@
 // Export main components
 export { DatabaseManager, getDatabase, initializeDatabase } from './Database.js';
 
-// Export hooks database
-export { HooksDatabase } from './HooksDatabase.js';
+// Export session store (CRUD operations for sessions, observations, summaries)
+export { SessionStore } from './SessionStore.js';
+
+// Export session search (FTS5 and structured search)
+export { SessionSearch } from './SessionSearch.js';
 
 // Export types
 export * from './types.js';