fix: Simplify notification logic - use direct or file, never both

- Check upfront if we have listeners for direct notifications
- Use EITHER direct notifications OR file watcher, not both
- This eliminates any possibility of duplicate broadcasts
- Server sessions get instant updates via direct notifications
- Forwarded sessions use optimized file watcher

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

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

web/src/server/services/stream-watcher.ts

@@ -206,12 +206,15 @@ export class StreamWatcher {
    * Start watching a file for changes
    */
   private startWatching(sessionId: string, streamPath: string, watcherInfo: WatcherInfo): void {
-    // First, set up direct notification listener for lowest latency
+    // Check if we should use direct notifications or file watching
-    let hasDirectNotifications = false;
+    const hasListeners = streamNotifier.hasListeners(sessionId);
 
+    if (hasListeners) {
+      console.log(`[STREAM] Using direct notifications for session ${sessionId}`);
+
+      // Set up direct notification listener for lowest latency
       watcherInfo.notificationListener = (update) => {
         if (update.sessionId === sessionId) {
-        hasDirectNotifications = true;
           // Process the notification data directly
           const lines = update.data.split('\n').filter((line) => line.trim());
           for (const line of lines) {
@@ -220,15 +223,10 @@ export class StreamWatcher {
         }
       };
       streamNotifier.on('stream-update', watcherInfo.notificationListener);
+    } else {
+      console.log(`[STREAM] Using file watcher for session ${sessionId} (cross-process)`);
 
-    // Only use file watcher if we're not getting direct notifications
+      // Use optimized file watcher for cross-process scenarios
-    // Give it a moment to see if we get direct notifications
-    setTimeout(() => {
-      if (!hasDirectNotifications) {
-        console.log(
-          `[STREAM] No direct notifications for session ${sessionId}, using file watcher`
-        );
-        // Use optimized file watcher as fallback (for cross-process scenarios)
       watcherInfo.watcher = new OptimizedFileWatcher(streamPath, { persistent: true });
 
       watcherInfo.watcher.on('change', (stats) => {
@@ -269,9 +267,6 @@ export class StreamWatcher {
       // Start the watcher
       watcherInfo.watcher.start();
     }
-    }, 100); // Wait 100ms to see if we get direct notifications
-
-    console.log(`[STREAM] Started watching for session ${sessionId}`);
   }
 
   /**