fix: 修复 cacheManager bean 冲突问题

- 重命名 cacheManager bean 为 knowledgeGraphCacheManager 和 dataManagementCacheManager
- 更新所有引用处（@Cacheable、@Qualifier 注解）
- 添加 @Primary 注解到 knowledgeGraphCacheManager 避免多 bean 冲突
- 修复文件：
  - DataManagementConfig.java
  - RedisCacheConfig.java
  - GraphEntityService.java
  - GraphQueryService.java
  - GraphCacheService.java
  - CacheableIntegrationTest.java

backend/services/data-management-service/src/main/java/com/datamate/datamanagement/infrastructure/config/DataManagementConfig.java

@@ -21,8 +21,8 @@ public class DataManagementConfig {
     /**
      * 缓存管理器
      */
-    @Bean
-    public CacheManager cacheManager() {
+    @Bean("dataManagementCacheManager")
+    public CacheManager dataManagementCacheManager() {
         return new ConcurrentMapCacheManager("datasets", "datasetFiles", "tags");
     }