fix(logging): 修复 uvicorn.error 日志在文件中重复打印的问题;

为 uvicorn.error logger 显式配置 handlers 与 propagate=False，
阻断经父 logger uvicorn 二次传播至文件 handler 的路径。

🤖 Generated with [Claude Code](https://github.com/claude), [CodeX](https://openai.com), [Gemini](https://github.com/apps/gemini-code-assist)
Co-Authored-By: Aurelius Huang<threefish.ai@gmail.com>

Author: ThreeFish-AI

src/coding/proxy/logging/__init__.py

@@ -118,7 +118,7 @@ def build_log_config(
         },
         "loggers": {
             "uvicorn": {"handlers": ["default"], "level": level, "propagate": False},
-            "uvicorn.error": {"level": level},
+            "uvicorn.error": {"handlers": ["default"], "level": level, "propagate": False},
             "uvicorn.access": {
                 "handlers": ["access"],
                 "level": "INFO",