fix: banner translations and deployment improvements

- Add translateCarName import from i18n.ts for proper multilingual support
- Change default API language from 'ko' to 'en' for hero banners
- Add checkbox column for Local Cars banner registration
- Update Dockerfile with Playwright dependencies
- Add PostgreSQL migration script
- Add banner translation fix script

🤖 Generated with [Claude Code](https://claude.ai/claude-code)

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

backend/app/api/hero_banners.py

@@ -40,7 +40,7 @@ def get_localized_field(obj, field: str, lang: str) -> Optional[str]:
 
 @router.get("/", response_model=List[HeroBannerLocalizedResponse])
 def get_hero_banners(
-    lang: str = Query("ko", regex="^(ko|en|mn|ru)$"),
+    lang: str = Query("en", regex="^(ko|en|mn|ru)$"),
     db: Session = Depends(get_db)
 ):
     """활성 히어로 배너 목록 조회 (Public)"""