fix(FN-1952): restore pi auth and extension loading

packages/dashboard/src/agent-generation.ts

@@ -57,8 +57,11 @@ async function initEngine() {
   }
 }
 
-// Initialize on module load (will be awaited in actual usage)
-const engineReady = initEngine();
+let engineReady: Promise<void> | undefined;
+function ensureEngineReady() {
+  engineReady ??= initEngine();
+  return engineReady;
+}
 
 // ── Constants ───────────────────────────────────────────────────────────────
 
@@ -212,6 +215,7 @@ function cleanupExpiredSessions(): void {
 }
 
 const cleanupInterval = setInterval(cleanupExpiredSessions, CLEANUP_INTERVAL_MS);
+cleanupInterval.unref?.();
 
 process.on("beforeExit", () => {
   clearInterval(cleanupInterval);
@@ -461,7 +465,7 @@ export async function generateAgentSpec(
   }
 
   try {
-    await engineReady;
+    await ensureEngineReady();
     await promptCatalogReadyPromise;
     const spec = await generateSpecWithAI(session, rootDir, promptOverrides);
     session.spec = spec;