fix: 配置清华 PyPI 镜像加速 Python 依赖下载

backend/Dockerfile

@@ -14,9 +14,9 @@ RUN apt-get update && apt-get install \
     -y --no-install-recommends && \
     rm -rf /var/lib/apt/lists/*
 
-# Install Python dependencies
+# Install Python dependencies (use Tsinghua mirror for faster download in China)
 COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+RUN pip install --no-cache-dir -r requirements.txt -i https://pypi.tuna.tsinghua.edu.cn/simple --trusted-host pypi.tuna.tsinghua.edu.cn
 
 # Copy project
 COPY . .

backend/requirements.txt

@@ -8,4 +8,5 @@ Pillow>=10.0
 graphene-django>=3.1
 django-filter>=23.0
 gunicorn>=21.0
-whitenoise>=6.5
+whitenoise>=6.5
+django-extensions>=3.2