feat: 企业微信 Phase 1 — token 续期 + 回调验证 + 调度器注册

wecom.py:
- Token 自动续期 (7200s 过期 + 60s 提前量 + 42001 重试)
- POST 请求自动重试 (最多 3 次，含速率限制退避)
- 新增 send_markdown_message() / send_template_card() 富消息方法

wecom.py API:
- GET /api/wecom/callback: 企微回调 URL 验证 (SHA1 签名 + AES 解密)
- POST /api/wecom/callback: 事件接收占位

scheduler.py:
- 仅推送给已绑定 wecom_userid 的经理
- 消息内容优化 (已填报/未填报人数统计)

main.py:
- APScheduler 注册每日 17:30 自动检查填报

已验证: WECOM_TOKEN 获取成功

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

backend/app/services/scheduler.py

@@ -15,8 +15,10 @@ async def check_daily_reporting(db: AsyncSession) -> dict:
     if weekday >= 5:  # Skip weekends
         return {"status": "weekend", "date": str(today)}
 
-    # Get all managers
-    result = await db.execute(select(User).where(User.role == "manager"))
+    # Get all managers with wecom_userid
+    result = await db.execute(
+        select(User).where(User.role == "manager", User.wecom_userid.isnot(None))
+    )
     managers = result.scalars().all()
 
     # Get managers who have reported today
@@ -31,16 +33,25 @@ async def check_daily_reporting(db: AsyncSession) -> dict:
         reported_map[str(uid)] = True
 
     not_reported = []
+    reported_names = []
     for m in managers:
-        if str(m.id) not in reported_map:
+        if str(m.id) in reported_map:
+            reported_names.append(m.name)
+        else:
             not_reported.append(m)
 
-    if not_reported and managers:
-        content = f"📋 今日填报提醒（{today}）\n\n以下同事尚未提交今日拜访记录：\n"
-        for m in not_reported:
-            content += f"• {m.name}\n"
-        content += "\n请尽快完成今日拜访填报 🙏"
-
+    # Send markdown message to not-reported managers
+    if not_reported:
+        names = "、".join(m.name for m in not_reported)
+        content = (
+            f"## 📋 今日填报提醒\n\n"
+            f"> 日期：{today}\n"
+            f"> 已填报：{len(reported_names)} 人\n"
+            f"> 未填报：**{len(not_reported)} 人**\n\n"
+            f"以下同事尚未提交今日拜访记录：\n"
+            + "".join(f"- **{m.name}**\n" for m in not_reported)
+            + f"\n请尽快完成今日拜访填报 🙏"
+        )
         user_ids = [m.wecom_userid for m in not_reported if m.wecom_userid]
         if user_ids:
             await wecom_client.send_text_message(user_ids, content)