fix: CI/CD 워크플로우 checkout 에러 수정

- container 이미지(maven)에 Node.js 없어서 actions/checkout 실패
- git clone으로 대체
- .deploy-trigger 파일 생성 → systemd path unit이 감지하여 서비스 자동 재시작

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

.gitea/workflows/deploy.yml

@@ -12,7 +12,9 @@ jobs:
       image: maven:3.9-eclipse-temurin-17
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        run: |
+          git clone --depth=1 --branch=${GITHUB_REF_NAME} \
+            ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}.git .
 
       - name: Configure Maven settings
         run: |
@@ -39,8 +41,9 @@ jobs:
       - name: Build
         run: mvn clean package -DskipTests -B
 
-      - name: Deploy to server
+      - name: Deploy
         run: |
           cp target/gc-guide-api-*.jar /deploy/api/app.jar
-          echo "Deployed at $(date '+%Y-%m-%d %H:%M:%S')"
+          date '+%Y-%m-%d %H:%M:%S' > /deploy/api/.deploy-trigger
+          echo "Deployed at $(cat /deploy/api/.deploy-trigger)"
           ls -la /deploy/api/