feat: 企微菜单管理 — create_menu / get_menu / delete_menu

wecom.py 新增:
- create_menu(buttons) — 创建/替换应用自定义菜单
- get_menu() — 获取当前菜单配置
- delete_menu() — 删除菜单

API 新增:
- POST /api/wecom/setup-menu — 一键部署标准菜单(开始填报 + 绑定账号)
- GET /api/wecom/menu — 查看当前菜单

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

backend/app/api/wecom.py

@@ -137,6 +137,32 @@ async def test_message(
     return {"success": success, "sent_to": wecom_userid}
 
 
+@router.post("/setup-menu")
+async def setup_menu(current_user: dict = Depends(require_director)):
+    """Create the standard app menu (开始填报 + 绑定账号)."""
+    buttons = [
+        {
+            "type": "view",
+            "name": "📝 开始填报",
+            "url": "https://qj.dhdx.fun/m",
+        },
+        {
+            "type": "view",
+            "name": "🔗 绑定账号",
+            "url": "https://qj.dhdx.fun/bind-wechat",
+        },
+    ]
+    success = await wecom_client.create_menu(buttons)
+    return {"success": success, "message": "菜单已部署" if success else "菜单创建失败"}
+
+
+@router.get("/menu")
+async def get_menu(current_user: dict = Depends(require_director)):
+    """Get current app menu configuration."""
+    menu = await wecom_client.get_menu()
+    return menu or {"message": "No menu configured"}
+
+
 @router.post("/trigger-daily-check")
 async def trigger_daily_check(
     current_user: dict = Depends(require_director),