fix(bridge): 채널 중복 생성 race condition 수정 + AG- 접두사 + metadata 모니터링

watcher.py

@@ -118,7 +118,9 @@ class BrainEventHandler(FileSystemEventHandler):
 
         file_name = path.name
         if file_name not in Config.WATCHED_FILES:
-            return
+            # Check suffix patterns
+            if not any(file_name.endswith(s) for s in Config.WATCHED_SUFFIXES):
+                return
 
         if self._should_debounce(str(path)):
             return