fix: 直接加义工时的补录活动时间改为真实提交当天（不再是 2024-01-01 假时间）

- hours.ts POST /direct-add：
  · 不再复用单一『【补录】直接加义工时长』活动（之前 start_time
    硬编码 2024-01-01 00:00 会在所有活动列表/详情里显示错时间）
  · 改为每次提交取 SQLite datetime('now','+8 hours') 真实 UTC+8 时刻，
    活动标题按日期拼接：『【补录】YYYY-MM-DD 直接加义工时长』
  · start_time / end_time 都设为提交这一刻的 YYYY-MM-DD HH:MM，
    同一日内多次提交会复用同日期活动；不同日期自动建独立活动
  · 响应额外返回 direct_add_activity_title / direct_add_activity_time
    便于前端以后 toast 里显示
- 新增容错：last_insert_rowid() 取不到活动就 ROLLBACK + 返回 500，
  防止 hours 行悬挂到无效 activity_id

server/src/routes/hours.ts

@@ -36,7 +36,7 @@ router.post('/batch', authMiddleware, (req: AuthRequest, res: Response) => {
   }
 });
 
-const DIRECT_ADD_TITLE = '【补录】直接加义工时长';
+const DIRECT_ADD_TITLE_PREFIX = '【补录】';
 
 router.post('/direct-add', authMiddleware, (req: AuthRequest, res: Response) => {
   const { items } = req.body || {};
@@ -68,13 +68,21 @@ router.post('/direct-add', authMiddleware, (req: AuthRequest, res: Response) =>
       return res.status(400).json({ error: errors.join('；') });
     }
     db.execCompat('BEGIN');
-    let act = db.prepareCompat('SELECT * FROM activities WHERE title = ?').get(DIRECT_ADD_TITLE) as any;
+    const nowLocal = (db.prepareCompat(`SELECT datetime('now','+8 hours') AS ts`).get() as any)?.ts || new Date().toISOString().slice(0, 19).replace('T', ' ');
+    const dayStr = String(nowLocal).slice(0, 10);
+    const actTitle = `${DIRECT_ADD_TITLE_PREFIX}${dayStr} 直接加义工时长`;
+    let act = db.prepareCompat('SELECT * FROM activities WHERE title = ? AND DATE(start_time) = ?').get(actTitle, dayStr) as any;
     if (!act) {
+      const timeStr = String(nowLocal).slice(0, 16);
       db.prepareCompat(`
         INSERT INTO activities (title, content, start_time, end_time)
         VALUES (?, ?, ?, ?)
-      `).run(DIRECT_ADD_TITLE, '管理台直接补录义工时长，不绑定真实活动', '2024-01-01 00:00', '2099-12-31 23:59');
-      act = db.prepareCompat('SELECT * FROM activities WHERE title = ?').get(DIRECT_ADD_TITLE) as any;
+      `).run(actTitle, `管理台于 ${timeStr} 直接补录义工时长，不绑定真实活动`, timeStr, timeStr);
+      act = db.prepareCompat('SELECT * FROM activities WHERE id = last_insert_rowid()').get() as any;
+    }
+    if (!act) {
+      db.execCompat('ROLLBACK');
+      return res.status(500).json({ error: '无法创建补录活动记录' });
     }
     const insert = db.prepareCompat(`
       INSERT INTO hours (activity_id, user_id, hours, remark)
@@ -100,6 +108,8 @@ router.post('/direct-add', authMiddleware, (req: AuthRequest, res: Response) =>
       total_hours: results.reduce((s, r) => s + r.hours, 0),
       results,
       direct_add_activity_id: act.id,
+      direct_add_activity_title: act.title,
+      direct_add_activity_time: act.start_time,
     });
   } catch (e: any) {
     try { db.execCompat('ROLLBACK'); } catch {}