chore: 캐시 상세 설정

- ttl 설정
- maxSize 설정
- cache 통계 위한 metric 활성화

backend/src/main/java/reviewme/config/CacheManagerConfig.java

@@ -1,8 +1,10 @@
 package reviewme.config;
 
+import com.github.benmanes.caffeine.cache.Caffeine;
+import java.time.Duration;
 import org.springframework.cache.CacheManager;
 import org.springframework.cache.annotation.EnableCaching;
-import org.springframework.cache.concurrent.ConcurrentMapCacheManager;
+import org.springframework.cache.caffeine.CaffeineCacheManager;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Profile;
@@ -13,7 +15,17 @@
 public class CacheManagerConfig {
 
     @Bean
-    public CacheManager cacheManager() {
-        return new ConcurrentMapCacheManager();
+    public CacheManager cacheManager(Caffeine caffeine) {
+        CaffeineCacheManager caffeineCacheManager = new CaffeineCacheManager();
+        caffeineCacheManager.setCaffeine(caffeine);
+        return caffeineCacheManager;
+    }
+
+    @Bean
+    public Caffeine caffeineConfig() {
+        return Caffeine.newBuilder()
+                .expireAfterAccess(Duration.ofDays(30))
+                .maximumSize(1000)
+                .recordStats();
     }
 }