fix(backend): ddl-auto validate → none (PostGIS geometry 타입 검증 실패 해결)

backend/src/main/resources/application.yml

@@ -3,7 +3,7 @@ spring:
     active: ${SPRING_PROFILES_ACTIVE:local}
   jpa:
     hibernate:
-      ddl-auto: validate
+      ddl-auto: none
     properties:
       hibernate:
         default_schema: kcg