Replace rsync with git pull in CI workflow

Rsync was leaving dirty working trees on the deploy server, causing
git pull conflicts during manual deploys. Use git fetch + reset instead.

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

.gitea/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
 
       - name: Install tools
         run: |
-          apt-get update && apt-get install -y --no-install-recommends openssh-client rsync
+          apt-get update && apt-get install -y --no-install-recommends openssh-client
 
       - name: Set up SSH
         env:
@@ -28,18 +28,15 @@ jobs:
           chmod 600 ~/.ssh/id_rsa
           ssh-keyscan -H "$DEPLOY_HOST" >> ~/.ssh/known_hosts 2>/dev/null || true
 
-      - name: Sync code to server
+      - name: Pull latest code on server
         env:
           DEPLOY_HOST: ${{ secrets.DEPLOY_HOST }}
         run: |
-          rsync -avz --delete \
-            --exclude '.git' \
-            --exclude '__pycache__' \
-            --exclude '*.pyc' \
-            --exclude '.pytest_cache' \
-            --exclude 'venv' \
-            --exclude '.env' \
-            ./ "root@$DEPLOY_HOST:/root/art-dag/celery/"
+          ssh "root@$DEPLOY_HOST" "
+            cd /root/art-dag/celery
+            git fetch origin main
+            git reset --hard origin/main
+          "
 
       - name: Build and push image
         env: