feat: 审核通过移动文件到approved，拒绝删除pending文件

- StorageService 新增 delete()
- approve: 文件 pending → approved
- reject: 删除 pending 文件

par-api/src/main/java/com/par/api/controller/AdminController.java

@@ -135,6 +135,10 @@ public class AdminController {
 
         Long reviewerId = (Long) request.getAttribute("accountId");
 
+        // 删除 pending 文件
+        storageService.delete(config.getStoragePath());
+
+        config.setStoragePath(null);
         config.setStatus(ConfigStatus.REJECTED);
         config.setReviewerId(reviewerId);
         config.setReviewedAt(LocalDateTime.now());