perf: BuildKit + docker compose v2로 빌드 속도 개선

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/deploy.yml

@@ -8,6 +8,9 @@ on:
 jobs:
   deploy:
     runs-on: ubuntu-latest
+    env:
+      DOCKER_BUILDKIT: 1
+      COMPOSE_DOCKER_CLI_BUILD: 1
     steps:
       - name: Pull latest code
         run: |
@@ -23,7 +26,7 @@ jobs:
       - name: Build and Deploy
         run: |
           cd /home/three/startover/repo
-          docker-compose -f docker-compose.prod.yml --env-file .env.production up -d --build --remove-orphans
+          docker compose -f docker-compose.prod.yml --env-file .env.production up -d --build --remove-orphans
 
       - name: Wait for services
         run: sleep 15