fix(chat): image send 500 + table/newline formatting (v2026.07.20.1708)

backend/python/app/api/chat_service.py

@@ -1657,6 +1657,16 @@ async def _send_message_core(
 
 
 
+    # 媒体分支直接返回，不会进入 LLM 工具调用；提前初始化避免未绑定
+
+    called_skill_names = []
+
+
+
+    called_mcp_names = []
+
+
+
     if effective_skill_ids: