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/hooks/new-hook.ts

@@ -24,8 +24,20 @@ async function newHook(input?: UserPromptSubmitInput): Promise<void> {
   const { session_id, cwd, prompt } = input;
   const project = getProjectName(cwd);
 
+  console.log('[NEW-HOOK] Received hook input:', {
+    session_id: session_id,
+    has_prompt: !!prompt,
+    cwd: cwd
+  });
+
   const port = getWorkerPort();
 
+  console.log('[NEW-HOOK] Calling /api/sessions/init:', {
+    claudeSessionId: session_id,
+    project,
+    prompt_length: prompt?.length
+  });
+
   // Initialize session via HTTP - handles DB operations and privacy checks
   const initResponse = await fetch(`http://127.0.0.1:${port}/api/sessions/init`, {
     method: 'POST',
@@ -46,6 +58,12 @@ async function newHook(input?: UserPromptSubmitInput): Promise<void> {
   const sessionDbId = initResult.sessionDbId;
   const promptNumber = initResult.promptNumber;
 
+  console.log('[NEW-HOOK] Received from /api/sessions/init:', {
+    sessionDbId: sessionDbId,
+    promptNumber: promptNumber,
+    skipped: initResult.skipped
+  });
+
   // Check if prompt was entirely private (worker performs privacy check)
   if (initResult.skipped && initResult.reason === 'private') {
     console.error(`[new-hook] Session ${sessionDbId}, prompt #${promptNumber} (fully private - skipped)`);
@@ -59,6 +77,12 @@ async function newHook(input?: UserPromptSubmitInput): Promise<void> {
   // /review 101 → review 101 (more semantic for observations)
   const cleanedPrompt = prompt.startsWith('/') ? prompt.substring(1) : prompt;
 
+  console.log('[NEW-HOOK] Calling /sessions/{sessionDbId}/init:', {
+    sessionDbId: sessionDbId,
+    promptNumber: promptNumber,
+    userPrompt_length: cleanedPrompt?.length
+  });
+
   // Initialize SDK agent session via HTTP (starts the agent!)
   const response = await fetch(`http://127.0.0.1:${port}/sessions/${sessionDbId}/init`, {
     method: 'POST',