feat: Implement Phase 1 of SDK agent architecture with hook integration

- Added CLI commands for context, new session, save observation, and summary.
- Created HooksDatabase for managing SDK sessions and observations.
- Implemented migration 004 to add new tables: sdk_sessions, observation_queue, observations, and session_summaries.
- Developed hook functions for context display, session initialization, observation queuing, and session finalization.
- Added comprehensive tests for database schema and hook functionality.
- Documented Phase 1 implementation in PHASE1-COMPLETE.md.

src/services/sqlite/index.ts

@@ -9,6 +9,9 @@ export { DiagnosticsStore } from './DiagnosticsStore.js';
 export { TranscriptEventStore } from './TranscriptEventStore.js';
 export { StreamingSessionStore } from './StreamingSessionStore.js';
 
+// Export hooks database
+export { HooksDatabase } from './HooksDatabase.js';
+
 // Export types
 export * from './types.js';