fix: remove findBySecretKey from FeatureServiceRepository

secretKey field was removed from FeatureServiceEntity in the previous
refactor, but the repository method was left behind, crashing startup.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tenant-service/src/main/java/com/xuqm/tenant/repository/FeatureServiceRepository.java

@@ -12,5 +12,5 @@ public interface FeatureServiceRepository extends JpaRepository<FeatureServiceEn
             String appId,
             FeatureServiceEntity.Platform platform,
             FeatureServiceEntity.ServiceType serviceType);
-    Optional<FeatureServiceEntity> findBySecretKey(String secretKey);
+
 }