application.yml 통합 및 Azure Blob Storage 설정 추가

- application-dev.yml, application-local.yml 삭제
- 단일 application.yml로 통합 (user-service 형식 참고)
- Azure Blob Storage connection string 기본값 추가
- Redis, Actuator, Logging 상세 설정 추가
- OpenAPI/Swagger 설정 추가
- CORS 설정 추가
- 모든 설정을 환경 변수로 관리 가능하도록 구성

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

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

content-service/build.gradle

@@ -2,9 +2,13 @@ configurations {
     // Exclude JPA and PostgreSQL from inherited dependencies (Phase 3: Redis migration)
     implementation.exclude group: 'org.springframework.boot', module: 'spring-boot-starter-data-jpa'
     implementation.exclude group: 'org.postgresql', module: 'postgresql'
+
 }
 
 dependencies {
+
+    implementation 'org.springframework.boot:spring-boot-starter-actuator'
+
     // Redis for AI data reading and image URL caching
     implementation 'org.springframework.boot:spring-boot-starter-data-redis'