feat: 添加内容置顶功能，更新相关数据模型和前端视图

backend/app/services/common.go

@@ -101,7 +101,7 @@ func (s *common) InitUpload(ctx context.Context, userID int64, form *common_dto.
 		localPath = "./storage"
 	}
 	tempDir := filepath.Join(localPath, "temp", uploadID)
-	if err := os.MkdirAll(tempDir, 0755); err != nil {
+	if err := os.MkdirAll(tempDir, 0o755); err != nil {
 		return nil, errorx.ErrInternalError.WithCause(err)
 	}
 
@@ -205,7 +205,7 @@ func (s *common) CompleteUpload(ctx context.Context, userID int64, form *common_
 	}
 
 	hash := hex.EncodeToString(hasher.Sum(nil))
-	dst.Close(); // Ensure flush before potential removal
+	dst.Close() // Ensure flush before potential removal
 	os.RemoveAll(tempDir)
 
 	// Deduplication Logic (Similar to Upload)