fix: Remove all session validation to prevent continuation errors after /exit

Root cause: Hooks provide session_id as the source of truth. We were adding
unnecessary validation (checking if sessions exist, checking status, etc.)
which caused 409 conflicts when continuing sessions after /exit.

Changes:
1. worker-service.ts: Removed 409 "Session already exists" check in handleInit
2. SessionStore.ts: Made createSDKSession idempotent using INSERT OR IGNORE
3. new-hook.ts: Simplified to just call createSDKSession - no findActiveSDKSession,
   no reactivateSession logic, no status management
4. save-hook.ts: Removed session validation, use fixed port instead of session.worker_port
5. summary-hook.ts: Removed session validation, use fixed port instead of session.worker_port

Philosophy: Hooks manage lifecycle, we just save data with whatever session_id
they give us. No validation, no status checks, no guessing.

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

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

src/hooks/new.ts

@@ -31,54 +31,25 @@ export async function newHook(input?: UserPromptSubmitInput): Promise<void> {
   const db = new SessionStore();
 
   try {
-
-    // Check for any existing session (active, failed, or completed)
-    let existing = db.findActiveSDKSession(session_id);
-    let sessionDbId: number;
-    let isNewSession = false;
-
-    if (existing) {
-      // Session already active, increment prompt counter
-      sessionDbId = existing.id;
-      const promptNumber = db.incrementPromptCounter(sessionDbId);
-      console.error(`[new-hook] Continuing session ${sessionDbId}, prompt #${promptNumber}`);
-    } else {
-      // Check for inactive sessions we can reuse
-      const inactive = db.findAnySDKSession(session_id);
-
-      if (inactive) {
-        // Reactivate the existing session
-        sessionDbId = inactive.id;
-        db.reactivateSession(sessionDbId, prompt);
-        const promptNumber = db.incrementPromptCounter(sessionDbId);
-        isNewSession = true;
-        console.error(`[new-hook] Reactivated session ${sessionDbId}, prompt #${promptNumber}`);
-      } else {
-        // Create new session
-        sessionDbId = db.createSDKSession(session_id, project, prompt);
-        const promptNumber = db.incrementPromptCounter(sessionDbId);
-        isNewSession = true;
-        console.error(`[new-hook] Created new session ${sessionDbId}, prompt #${promptNumber}`);
-      }
-    }
+    // Just save session_id for indexing - no validation, no state management
+    const sessionDbId = db.createSDKSession(session_id, project, prompt);
+    const promptNumber = db.incrementPromptCounter(sessionDbId);
+    console.error(`[new-hook] Session ${sessionDbId}, prompt #${promptNumber}`);
 
     // Get fixed port
     const port = getWorkerPort();
 
-    // Only initialize worker on new sessions
-    if (isNewSession) {
-      // Initialize session via HTTP
-      const response = await fetch(`http://127.0.0.1:${port}/sessions/${sessionDbId}/init`, {
-        method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ project, userPrompt: prompt }),
-        signal: AbortSignal.timeout(5000)
-      });
+    // Initialize session via HTTP
+    const response = await fetch(`http://127.0.0.1:${port}/sessions/${sessionDbId}/init`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ project, userPrompt: prompt }),
+      signal: AbortSignal.timeout(5000)
+    });
 
-      if (!response.ok) {
-        const errorText = await response.text();
-        throw new Error(`Failed to initialize session: ${response.status} ${errorText}`);
-      }
+    if (!response.ok) {
+      const errorText = await response.text();
+      throw new Error(`Failed to initialize session: ${response.status} ${errorText}`);
     }
 
     console.log(createHookResponse('UserPromptSubmit', true));