feat: 初始化智能电量监控系统项目

该提交完成了完整的电费监控系统项目初始化，包含：
1.  后端Node.js+Express服务，支持定时采集、登录认证、数据API
2.  React前端界面，包含登录页和数据仪表盘
3.  Docker容器化配置和docker-compose部署文件
4.  环境变量示例和gitignore、dockerignore配置
5.  完整的项目文档README

Dockerfile

@@ -0,0 +1,37 @@
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+COPY package.json package-lock.json ./
+
+RUN npm ci --only=production && \
+    npm cache clean --force
+
+FROM node:20-alpine AS client-builder
+
+WORKDIR /app
+
+COPY client/package.json ./
+
+RUN npm install && npm cache clean --force
+
+COPY client/ ./
+
+RUN npm run build
+
+FROM node:20-alpine
+
+WORKDIR /app
+
+RUN apk add --no-cache tzdata ca-certificates
+
+ENV TZ=Asia/Shanghai
+
+COPY --from=builder /app/node_modules ./node_modules
+COPY server.js .
+COPY --from=client-builder /app/dist ./client/dist
+COPY data ./data
+
+EXPOSE 3000
+
+CMD ["node", "server.js"]