build: add ruff and pytest dependencies, install clang-format in image

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -16,6 +16,7 @@ RUN sed -i 's/deb.debian.org/mirrors.ustc.edu.cn/g' /etc/apt/sources.list.d/debi
 # 安装系统依赖
 RUN apt-get update && apt-get install -y \
     gcc \
+    clang-format \
     && rm -rf /var/lib/apt/lists/*
 
 # 复制项目文件