feat(chat): support chat resources, implement chat-based remote discovery via resource messages

backend/src/app.py

@@ -138,15 +138,15 @@ class App(ChatMixin):
         tools = []
         for spec in remote_specs or []:
             if isinstance(spec, str):
-                name, prefix = spec, ''
+                name, prefix = spec, None
             else:
-                name, prefix = spec.get('name'), spec.get('prefix', '')
+                name, prefix = spec.get('name'), spec.get('prefix', None)
             connection = self.remotes.get((user_id, name))
             if connection is None:
                 print(f"WARNING: remote '{name}' requested by run input is not connected, skipping")
                 continue
             for fn in connection.functions.values():
-                tools.append(RemoteToolSpec(connection, fn, name=prefix + fn.name))
+                tools.append(fn.get_spec(connection, prefix=prefix))
         return tools
 
     def resolve_remote_call(self, request_id, result=None, error=None):