feat: 优化编辑器 UI 和文件名显示，支持全屏编辑模式

backend/app/services/common.go

@@ -248,7 +248,8 @@ func (s *common) CompleteUpload(ctx context.Context, userID int64, form *common_
 			ObjectKey: objectKey,
 			Hash:      hash,
 			Meta: types.NewJSONType(fields.MediaAssetMeta{
-				Size: totalSize,
+				Filename: meta.Filename,
+				Size:     totalSize,
 			}),
 		}
 	}
@@ -384,7 +385,8 @@ func (s *common) Upload(
 			ObjectKey: objectKey,
 			Hash:      hash,
 			Meta: types.NewJSONType(fields.MediaAssetMeta{
-				Size: size,
+				Filename: file.Filename,
+				Size:     size,
 			}),
 		}
 	}
@@ -398,10 +400,14 @@ func (s *common) Upload(
 
 func (s *common) composeUploadResult(asset *models.MediaAsset) *common_dto.UploadResult {
 	url := s.GetAssetURL(asset.ObjectKey)
-	filename := filepath.Base(asset.ObjectKey)
-	// Try to get original filename if stored? Currently objectKey has UUID prefix.
-	// We can store original filename in Meta if needed. For now, just return valid result.
-	// Meta is JSONType wrapper.
+	filename := asset.Meta.Data().Filename
+	if filename == "" {
+		filename = filepath.Base(asset.ObjectKey)
+		// Try to strip UUID prefix (36 chars + 1 underscore = 37)
+		if len(filename) > 37 && filename[36] == '_' {
+			filename = filename[37:]
+		}
+	}
 	size := asset.Meta.Data().Size
 
 	return &common_dto.UploadResult{