fix: enhance session continuity by propagating session ID in SDKAgent and adding diagnostic logging

Added comprehensive diagnostic logging to trace session ID and prompt number flow through the entire system. This is Phase 1 of the session continuity regression fix.

Changes:
- Added logging in src/hooks/new-hook.ts (4 log points)
- Added logging in src/services/worker/http/routes/SessionRoutes.ts (4 log points)
- Added logging in src/services/worker/SessionManager.ts (4 log points)
- Added logging in src/services/worker/SDKAgent.ts (2 log points)

The logging will help identify where the session ID propagation breaks and whether prompt numbers are being calculated correctly.

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

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

src/services/worker/http/routes/SessionRoutes.ts

@@ -173,6 +173,12 @@ export class SessionRoutes extends BaseRouteHandler {
     if (sessionDbId === null) return;
 
     const { userPrompt, promptNumber } = req.body;
+    console.log('[SESSION-ROUTES] handleSessionInit called:', {
+      sessionDbId,
+      promptNumber,
+      has_userPrompt: !!userPrompt
+    });
+
     const session = this.sessionManager.initializeSession(sessionDbId, userPrompt, promptNumber);
 
     // Get the latest user_prompt for this session to sync to Chroma
@@ -482,6 +488,12 @@ export class SessionRoutes extends BaseRouteHandler {
   private handleSessionInitByClaudeId = this.wrapHandler((req: Request, res: Response): void => {
     const { claudeSessionId, project, prompt } = req.body;
 
+    console.log('[SESSION-ROUTES] handleSessionInitByClaudeId called:', {
+      claudeSessionId,
+      project,
+      prompt_length: prompt?.length
+    });
+
     // Validate required parameters
     if (!this.validateRequired(req, res, ['claudeSessionId', 'project', 'prompt'])) {
       return;
@@ -492,10 +504,21 @@ export class SessionRoutes extends BaseRouteHandler {
     // Step 1: Create/get SDK session (idempotent INSERT OR IGNORE)
     const sessionDbId = store.createSDKSession(claudeSessionId, project, prompt);
 
+    console.log('[SESSION-ROUTES] createSDKSession returned:', {
+      sessionDbId,
+      claudeSessionId
+    });
+
     // Step 2: Get next prompt number from user_prompts count
     const currentCount = store.getPromptNumberFromUserPrompts(claudeSessionId);
     const promptNumber = currentCount + 1;
 
+    console.log('[SESSION-ROUTES] Calculated promptNumber:', {
+      sessionDbId,
+      promptNumber,
+      currentCount
+    });
+
     // Step 3: Strip privacy tags from prompt
     const cleanedPrompt = stripMemoryTagsFromPrompt(prompt);