修复后端构建，添加pnpm-workspace.yaml

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

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

Dockerfile

@@ -23,9 +23,9 @@ FROM node:20-alpine AS backend-builder
 
 WORKDIR /app
 
-# 复制后端代码
+# 复制后端代码和配置
 COPY apps/backend ./apps/backend
-COPY package.json ./
+COPY package.json pnpm-workspace.yaml ./
 
 # 安装pnpm和依赖
 RUN npm install -g pnpm@9 && \