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

server/src/routes/export.ts

@@ -0,0 +1,71 @@
+import { Router } from 'express';
+import { getDb } from '../db';
+import { authMiddleware, AuthRequest } from '../middleware/auth';
+
+const router = Router();
+
+router.post('/', authMiddleware, (req: AuthRequest, res) => {
+  const { include_users, include_activities, include_hours, include_user_totals, include_user_activities } = req.body || {};
+  const db = getDb();
+  const result: any = {};
+
+  if (include_users) {
+    result.users = db.prepareCompat(`
+      SELECT u.id, u.class, u.name, u.volunteer_no, g.name AS group_name
+      FROM users u LEFT JOIN work_groups g ON u.group_id = g.id
+      ORDER BY u.class, u.name
+    `).all();
+  }
+  if (include_activities) {
+    result.activities = db.prepareCompat(`
+      SELECT a.*, GROUP_CONCAT(g.name) AS groups_name
+      FROM activities a
+      LEFT JOIN activity_groups ag ON a.id = ag.activity_id
+      LEFT JOIN work_groups g ON ag.group_id = g.id
+      GROUP BY a.id
+      ORDER BY a.start_time DESC
+    `).all();
+  }
+  if (include_hours) {
+    result.hours = db.prepareCompat(`
+      SELECT h.hours, h.remark, h.created_at,
+             a.title AS activity_title, a.start_time, a.end_time,
+             u.class, u.name, u.volunteer_no, g.name AS group_name
+      FROM hours h
+      JOIN activities a ON h.activity_id = a.id
+      JOIN users u ON h.user_id = u.id
+      LEFT JOIN work_groups g ON u.group_id = g.id
+      ORDER BY a.start_time DESC, u.class, u.name
+    `).all();
+  }
+  if (include_user_totals) {
+    result.user_totals = db.prepareCompat(`
+      SELECT u.id, u.class, u.name, u.volunteer_no, g.name AS group_name,
+             COALESCE(SUM(h.hours), 0) AS total_hours,
+             COUNT(DISTINCT h.activity_id) AS activity_count
+      FROM users u
+      LEFT JOIN work_groups g ON u.group_id = g.id
+      LEFT JOIN hours h ON h.user_id = u.id
+      GROUP BY u.id
+      ORDER BY total_hours DESC, u.class, u.name
+    `).all();
+  }
+  if (include_user_activities) {
+    const users = db.prepareCompat(`
+      SELECT u.id, u.class, u.name, u.volunteer_no, g.name AS group_name
+      FROM users u LEFT JOIN work_groups g ON u.group_id = g.id
+      ORDER BY u.class, u.name
+    `).all() as any[];
+    result.user_activities = users.map((u) => {
+      const acts = db.prepareCompat(`
+        SELECT a.title, a.start_time, a.end_time, h.hours, h.remark
+        FROM hours h JOIN activities a ON h.activity_id = a.id
+        WHERE h.user_id = ? ORDER BY a.start_time DESC
+      `).all(u.id);
+      return { ...u, activities: acts };
+    });
+  }
+  res.json(result);
+});
+
+export default router;