feat(hermes): switch to call_on_each_event with proper narrow filter

hermes-zulip-plugin/src/hermes_zulip/adapter.py

@@ -125,12 +125,20 @@ class ZulipAdapter:
     def _event_loop(self) -> None:
         """Background thread to listen for Zulip events.
         Creates a dedicated asyncio event loop for this thead (Python 3.13+).
+        Uses call_on_each_event (not call_on_each_message) for proper @mention detection.
         """
         loop = asyncio.new_event_loop()
         asyncio.set_event_loop(loop)
         try:
-            self._client.call_on_each_message(
+            # Build narrow to filter for our stream only
+            stream = self.config['zulip']['stream']
+            narrow = [[u"stream", stream]]
+            logger.info(f"Zulip: call_on_each_event narrow=[{narrow}]")
+
+            self._client.call_on_each_event(
                 lambda event: self._process_event(event),
+                event_types=["message"],
+                narrow=narrow,
             )
         except Exception as e:
             logger.error(f"Event loop crashed: {e}")
@@ -142,7 +150,15 @@ class ZulipAdapter:
     def _process_event(self, event: Dict[str, Any]) -> None:
         """Bridge the synchronous event to the async on_event handler."""
         event_type = str(event.get("type", "unknown"))
-        logger.info(f"[ZULIP_EVENT] Processing: {event_type}")
+        flags = event.get("flags", [])
+        sender_email = event.get("sender_email", "unknown")
+        sender_id = event.get("sender_id", 0)
+        logger.info(f"[ZULIP_EVENT] type={event_type} flags={flags} sender_id={sender_id} sender_email={sender_email}")
+        
+        # Check if this message is mentioned to us
+        is_mentioned = "mentioned" in flags
+        logger.info(f"[DEBUG] is_mentioned (via flags)={is_mentioned}")
+        
         try:
             loop = asyncio.get_event_loop()
             if loop.is_running():