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/sqlite/SessionSearch.ts

@@ -481,7 +481,7 @@ export class SessionSearch {
       const sql = `
         SELECT up.*
         FROM user_prompts up
-        JOIN sdk_sessions s ON up.claude_session_id = s.claude_session_id
+        JOIN sdk_sessions s ON up.content_session_id = s.content_session_id
         ${whereClause}
         ${orderClause}
         LIMIT ? OFFSET ?
@@ -498,23 +498,23 @@ export class SessionSearch {
   }
 
   /**
-   * Get all prompts for a session by claude_session_id
+   * Get all prompts for a session by content_session_id
    */
-  getUserPromptsBySession(claudeSessionId: string): UserPromptRow[] {
+  getUserPromptsBySession(contentSessionId: string): UserPromptRow[] {
     const stmt = this.db.prepare(`
       SELECT
         id,
-        claude_session_id,
+        content_session_id,
         prompt_number,
         prompt_text,
         created_at,
         created_at_epoch
       FROM user_prompts
-      WHERE claude_session_id = ?
+      WHERE content_session_id = ?
       ORDER BY prompt_number ASC
     `);
 
-    return stmt.all(claudeSessionId) as UserPromptRow[];
+    return stmt.all(contentSessionId) as UserPromptRow[];
   }
 
   /**