modify: 性能优化

test_mqtt_custom_topics.py

@@ -7,7 +7,7 @@ MQTT Bridge 自定义订阅主题单元测试
   3. 内置 chongming/... 主题兜底逻辑不变
 """
 import asyncio
-import json
+import orjson
 import sys
 from pathlib import Path
 from unittest.mock import MagicMock
@@ -24,7 +24,7 @@ from chongming.app.core.mqtt_bridge import (
 def make_msg(topic, payload):
     m = MagicMock()
     m.topic = topic
-    m.data = json.dumps(payload).encode("utf-8")
+    m.data = orjson.dumps(payload)
     return m