Content Service API 경로 표준화

- API 경로를 /content에서 /api/v1/content로 변경
- REST API 버저닝 패턴 적용 (/api/v1/서비스명)
- ContentController.java의 @RequestMapping 수정
- OpenAPI 명세서 경로 업데이트 (7개 엔드포인트)
- Javadoc 주석의 API 경로 정보 업데이트

영향 범위: content-service만 수정, common 모듈 변경 없음

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

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

content-service/src/main/resources/application.yml

@@ -4,31 +4,39 @@ spring:
 
   data:
     redis:
-      host: 20.214.210.71
-      port: 6379
-      password: Hi5Jessica!
+      host: ${REDIS_HOST:localhost}
+      port: ${REDIS_PORT:6379}
+      password: ${REDIS_PASSWORD:}
 
   kafka:
-    bootstrap-servers: 20.249.125.115:9092
+    bootstrap-servers: ${KAFKA_BOOTSTRAP_SERVERS:localhost:9092}
     consumer:
-      group-id: content-service-consumers
+      group-id: ${KAFKA_CONSUMER_GROUP_ID:content-service-consumers}
       auto-offset-reset: earliest
       key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
       value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
 
 server:
-  port: 8084
+  port: ${SERVER_PORT:8084}
 
 jwt:
-  secret: kt-event-marketing-jwt-secret-key-for-authentication-and-authorization-2025
-  access-token-validity: 3600000
-  refresh-token-validity: 604800000
+  secret: ${JWT_SECRET:dev-jwt-secret-key}
+  access-token-validity: ${JWT_ACCESS_TOKEN_VALIDITY:3600000}
+  refresh-token-validity: ${JWT_REFRESH_TOKEN_VALIDITY:604800000}
 
 azure:
   storage:
     connection-string: ${AZURE_STORAGE_CONNECTION_STRING:}
-    container-name: event-images
+    container-name: ${AZURE_CONTAINER_NAME:event-images}
 
 logging:
   level:
-    com.kt.event: DEBUG
+    com.kt.event: ${LOG_LEVEL_APP:DEBUG}
+    root: ${LOG_LEVEL_ROOT:INFO}
+  file:
+    name: ${LOG_FILE:logs/content-service.log}
+  logback:
+    rollingpolicy:
+      max-file-size: 10MB
+      max-history: 7
+      total-size-cap: 100MB