fix: resolve smtp authentication error and notification issues

- Stripped literal quotes from SMTP credentials in nodemailer config to prevent '535 Incorrect auth data' in Docker Swarm.

- Reduced notification polling interval from 60s to 10s for real-time updates.

- Fixed browser autoplay block for audio notifications by properly initializing the audio context.

components/Layout.tsx

@@ -46,12 +46,24 @@ export const Layout: React.FC<{ children: React.ReactNode }> = ({ children }) =>
   const unreadCount = notifications.filter(n => !n.is_read).length;
   const previousUnreadCountRef = React.useRef(0);
   const isInitialLoadRef = React.useRef(true);
+  
+  // Pre-initialize audio to ensure it's loaded and ready
+  const audioRef = React.useRef<HTMLAudioElement | null>(null);
+  useEffect(() => {
+    // Determine base path correctly whether in prod or dev
+    const basePath = import.meta.env.PROD ? '' : 'http://localhost:3001';
+    audioRef.current = new Audio(`${basePath}/audio/notification.mp3`);
+    audioRef.current.volume = 0.5;
+  }, []);
 
   const playNotificationSound = () => {
-    if (currentUser?.sound_enabled !== false) {
-      const audio = new Audio('/audio/notification.mp3');
-      audio.volume = 0.5;
-      audio.play().catch(e => console.log('Audio play failed:', e));
+    if (currentUser?.sound_enabled !== false && audioRef.current) {
+      // Reset time to 0 to allow rapid replays
+      audioRef.current.currentTime = 0;
+      const playPromise = audioRef.current.play();
+      if (playPromise !== undefined) {
+        playPromise.catch(e => console.log('Audio play blocked by browser policy:', e));
+      }
     }
   };