fix(agent): await endExecution in onAgentLoopEnd for streaming mode

In streaming mode, onAgentLoopEnd called endExecution() as fire-and-forget
(.catch() without await), so the cleanup handler that sends the
agent_run_end event could complete after the method returned. This caused
the Web UI to never receive the termination signal, leaving it stuck in
a spinning state.

Properly await endExecution() to ensure the agent_run_end event is sent
before the streaming promise chain completes.

Closes #1061

Author: Br1an67

multimodal/tarko/agent/src/agent/agent.ts

@@ -616,9 +616,11 @@ Provide concise and accurate responses.`;
 
     // End execution if not already ended
     if (this.executionController.isExecuting()) {
-      this.executionController.endExecution(AgentStatus.IDLE).catch((err) => {
+      try {
+        await this.executionController.endExecution(AgentStatus.IDLE);
+      } catch (err) {
         this.logger.error(`Error ending execution: ${err}`);
-      });
+      }
     }
   }