Fix critical bug: getSessionById missing claude_session_id

Critical bugfix for NOT NULL constraint violation.

Problem:
- Worker service calls getSessionById(sessionDbId) to fetch session data
- Worker then uses dbSession.claude_session_id to create ActiveSession
- But getSessionById was NOT selecting claude_session_id from database
- Result: claudeSessionId = undefined in worker
- Caused: "NOT NULL constraint failed: sdk_sessions.claude_session_id" errors
- Impact: Observations and summaries couldn't be stored

Root cause:
- SessionStore.getSessionById() SQL query missing claude_session_id column
- Line 710-713: "SELECT id, sdk_session_id, project, user_prompt"
- Should be: "SELECT id, claude_session_id, sdk_session_id, project, user_prompt"

Fix:
- Added claude_session_id to SELECT query in getSessionById
- Updated return type to include claude_session_id: string
- Now worker correctly receives claude_session_id from database
- Session ID from hook flows properly through entire system

Files changed:
- src/services/sqlite/SessionStore.ts (getSessionById method)

Testing:
- Build succeeded
- Ready for PM2 restart and live testing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

plugin/scripts/worker-service.cjs

@@ -282,7 +282,7 @@ ${e.stack}`:e.message;if(Array.isArray(e))return`[${e.length} items]`;let r=Obje
       FROM observations
       WHERE sdk_session_id = ?
     `).all(e),i=new Set,s=new Set;for(let n of t){if(n.files_read)try{let o=JSON.parse(n.files_read);Array.isArray(o)&&o.forEach(p=>i.add(p))}catch{}if(n.files_modified)try{let o=JSON.parse(n.files_modified);Array.isArray(o)&&o.forEach(p=>s.add(p))}catch{}}return{filesRead:Array.from(i),filesModified:Array.from(s)}}getSessionById(e){return this.db.prepare(`
-      SELECT id, sdk_session_id, project, user_prompt
+      SELECT id, claude_session_id, sdk_session_id, project, user_prompt
       FROM sdk_sessions
       WHERE id = ?
       LIMIT 1