refactor: 移除企微Webhook机器人代码，修复VLM日志

- 删除 wechat_service.send_webhook_alarm 方法
- 删除 config.py 中 webhook_url 配置
- 简化 notify_dispatch 通知逻辑（仅保留应用消息）
- 修复 vlm_service 使用项目统一 logger
- 添加 VLM 调用 URL 调试日志

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/services/notify_dispatch.py

@@ -97,26 +97,8 @@ async def process_alarm_notification(alarm_data: Dict):
             event_time.strftime("%Y-%m-%d %H:%M:%S")
             if isinstance(event_time, datetime) else str(event_time or "")
         )
-        detail_url = f"{service_base_url}/static/alarm_detail.html?alarm_id={alarm_id}"
 
-        sent = False
-
-        # 优先 Webhook（无需IP白名单）
-        if settings.wechat.webhook_url:
-            sent = await wechat_service.send_webhook_alarm(
-                webhook_url=settings.wechat.webhook_url,
-                alarm_id=alarm_id,
-                alarm_type=alarm_type,
-                area_name=area_name,
-                camera_name=camera_name,
-                description=description,
-                event_time=event_time_str,
-                alarm_level=alarm_level,
-                detail_url=detail_url,
-            )
-
-        # Webhook 未配置或失败时，降级到应用消息
-        if not sent and wechat_service.enabled:
+        if wechat_service.enabled:
             user_ids = [p["wechat_uid"] for p in persons]
             sent = await wechat_service.send_alarm_card(
                 user_ids=user_ids,
@@ -130,11 +112,12 @@ async def process_alarm_notification(alarm_data: Dict):
                 alarm_level=alarm_level,
                 service_base_url=service_base_url,
             )
-
-        if not sent:
-            logger.warning(f"告警通知未发送: {alarm_id}, webhook和应用消息均未成功")
+            if sent:
+                logger.info(f"告警通知完成: {alarm_id}")
+            else:
+                logger.warning(f"告警通知发送失败: {alarm_id}")
         else:
-            logger.info(f"告警通知完成: {alarm_id}")
+            logger.info(f"企微未启用，跳过通知: {alarm_id}")
 
     except Exception as e:
         logger.error(f"告警通知处理失败: {alarm_id}, error={e}", exc_info=True)