perf(identity-service): 添加 Docker 构建镜像加速

- Alpine: 使用 mirrors.aliyun.com
- Debian: 使用 mirrors.aliyun.com
- npm: 使用 registry.npmmirror.com (淘宝镜像)

加速中国区 Docker 构建速度

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/services/identity-service/Dockerfile

@@ -5,6 +5,12 @@
 # Build stage - use Alpine for smaller build context
 FROM node:20-alpine AS builder
 
+# Use Aliyun mirror for Alpine packages (China acceleration)
+RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories
+
+# Use taobao npm registry (China acceleration)
+RUN npm config set registry https://registry.npmmirror.com
+
 WORKDIR /app
 
 # Copy package files
@@ -35,12 +41,19 @@ FROM node:20-slim
 
 WORKDIR /app
 
+# Use Aliyun mirror for Debian packages (China acceleration)
+RUN sed -i 's/deb.debian.org/mirrors.aliyun.com/g' /etc/apt/sources.list.d/debian.sources 2>/dev/null || \
+    sed -i 's/deb.debian.org/mirrors.aliyun.com/g' /etc/apt/sources.list 2>/dev/null || true
+
 # Install OpenSSL and curl for health checks
 RUN apt-get update && apt-get install -y --no-install-recommends \
     openssl \
     curl \
     && rm -rf /var/lib/apt/lists/*
 
+# Use taobao npm registry (China acceleration)
+RUN npm config set registry https://registry.npmmirror.com
+
 # Install production dependencies only
 COPY package*.json ./
 RUN npm ci --only=production