chore: GitHub Actions 실행 주기 조정 (#16)

- collect-realtime: 15분마다(24시간) → 1시간마다(운행시간 05:00~00:59 KST만)
- collect-environment: 매시간 → 3시간마다

GitHub Actions 무료 플랜 분(minutes) 한도 준수 및 불필요한 리소스 사용 절감

https://claude.ai/code/session_01PLrPbYeCgEphovNQ25PLBk

Co-authored-by: Claude <noreply@anthropic.com>

Author: brody-0125

.github/workflows/collect-environment.yml

@@ -2,7 +2,7 @@ name: Collect Environment Data
 
 on:
   schedule:
-    - cron: '0 * * * *'
+    - cron: '0 */3 * * *'  # Every 3 hours
   workflow_dispatch:
 
 permissions:

.github/workflows/collect-realtime.yml

@@ -2,7 +2,7 @@ name: Collect Realtime Facility Status
 
 on:
   schedule:
-    - cron: '*/15 * * * *'
+    - cron: '0 20-15 * * *'  # Every hour during Seoul Metro operating hours (05:00~00:59 KST, UTC+9)
   workflow_dispatch:
 
 permissions: