feat: 初始化义工时长管理系统

- 管理台：活动设置、时长登记、用户管理、数据导出（Excel/PNG）
- 用户端：姓名查询个人义工时长与活动记录
- 技术栈：React + Vite + TailwindCSS / Node.js + Express + sql.js (SQLite)
- 支持 Docker 部署，附带 Gitea Actions 自动部署工作流
- 响应式界面，兼容移动端与 PC 端
- 默认管理员账号：admin / admin123

Dockerfile

@@ -0,0 +1,32 @@
+FROM node:20-alpine AS client-build
+WORKDIR /app/client
+COPY client/package.json client/package-lock.json* ./
+RUN npm install --no-audit --no-fund
+COPY client/ ./
+RUN npm run build
+
+FROM node:20-alpine AS server-build
+WORKDIR /app/server
+COPY server/package.json server/package-lock.json* ./
+RUN npm install --no-audit --no-fund
+COPY server/ ./
+RUN npm run build
+
+FROM node:20-alpine AS runtime
+WORKDIR /app
+ENV NODE_ENV=production
+ENV PORT=3000
+
+COPY server/package.json server/package-lock.json* ./
+RUN npm install --omit=dev --no-audit --no-fund
+
+COPY --from=client-build /app/client/dist ./client/dist
+COPY --from=server-build /app/server/dist ./server/dist
+COPY server/src/db/schema.sql ./server/src/db/schema.sql
+
+RUN mkdir -p ./server/data
+VOLUME ["/app/server/data"]
+
+EXPOSE 3000
+WORKDIR /app/server
+CMD ["node", "dist/index.js"]