fix(session): Semantic renaming and memory session ID capture for resume

This commit fixes the session ID confusion identified in PR #475:

PROBLEM:
- Using contentSessionId (user's Claude Code session) for SDK resume was wrong
- Memory agent conversation should persist across the entire user session
- Each SDK call was starting fresh, losing memory agent continuity

SOLUTION:
1. Semantic Renaming (clarity):
   - claudeSessionId → contentSessionId (user's observed session)
   - sdkSessionId → memorySessionId (memory agent's session for resume)
   - Database migration 17 renames columns accordingly

2. Memory Session ID Capture:
   - SDKAgent captures session_id from first SDK message
   - Persists to database via updateMemorySessionId()
   - SessionManager loads memorySessionId on session init

3. Resume Logic Fixed:
   - Only resume if memorySessionId captured from previous interaction
   - Enables memory agent continuity across user prompts

Files changed: 33 (types, database, agents, hooks, routes)

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/services/worker/DatabaseManager.ts

@@ -93,8 +93,8 @@ export class DatabaseManager {
    */
   getSessionById(sessionDbId: number): {
     id: number;
-    claude_session_id: string;
-    sdk_session_id: string | null;
+    content_session_id: string;
+    memory_session_id: string | null;
     project: string;
     user_prompt: string;
   } {