SMS 기능 연동 설정 및 테스트 추가

docker-compose.yaml

@@ -6,6 +6,8 @@ services:
       context: ./backend
       dockerfile: Dockerfile
     container_name: baron_backend
+    env_file:
+      - .env
     environment:
       - APP_ENV=${APP_ENV:-development}
       - COOKIE_SECRET=${COOKIE_SECRET}