Mattermost 웹훅 URL 설정 확인 로직 추가

.gitea/workflows/main.yml

@@ -2,7 +2,7 @@
 name: Run Report Table
 on:
   schedule:
-    - cron: "11 4 * * *"
+    - cron: "18 4 * * *"
 jobs:
   run-script:
     runs-on: ubuntu-latest

src/services/reporter.py

@@ -10,6 +10,10 @@ def post_mattermost(webhook: str, lines: List[str]) -> None:
     """
     Mattermost Webhook으로 메시지 전송.
     """
+    if not webhook:
+        logger.error("[MATTERMOST ERROR] Webhook URL is not configured.")
+        return
+
     payload = {
         "username": "Grafana Reporter",
         "icon_url": "https://grafana.com/static/assets/img/fav32.png",