refactor(storage): drop per-upload storage_driver, use storage_config as single source

Remove w_uploads.storage_driver and route all read/write/delete paths through
storage.Active() backed by storage_config.driver. Block direct driver switches
when uploads exist; require migration task instead. Simplify migration to
cursor-based file_path iteration without per-row driver updates.

internal/apps/upload/handler/file_management_test.go

@@ -29,7 +29,6 @@ func TestGetDistinctUploadTypes(t *testing.T) {
 		FileSize:      10,
 		MimeType:      "text/plain",
 		Extension:     "txt",
-		StorageDriver: "local",
 		Type:          "custom_type_xyz",
 		Status:        model.UploadStatusUsed,
 	}

internal/apps/upload/handler/logics.go

@@ -124,7 +124,6 @@ func createInstantUpload(ctx context.Context, existing model.Upload, input insta
 		MimeType:      input.MimeType,
 		Extension:     input.Extension,
 		Hash:          input.FileHash,
-		StorageDriver: existing.StorageDriver,
 		Type:          input.UploadType,
 		Status:        model.UploadStatusUsed,
 		AccessMode:    input.AccessMode,
@@ -142,9 +141,9 @@ func findReusableUpload(ctx context.Context, hash string, size int64) (model.Upl
 	return repository.FindReusableUploadByHash(ctx, hash, size)
 }
 
-func saveNewUploadRecord(ctx context.Context, upload *model.Upload, storageDriver, filePath string) error {
+func saveNewUploadRecord(ctx context.Context, upload *model.Upload, filePath string) error {
 	if err := repository.CreateUpload(ctx, upload); err != nil {
-		backend, backendErr := storage.ForDriver(ctx, storage.Driver(storageDriver))
+		_, backend, backendErr := storage.Active(ctx)
 		if backendErr == nil {
 			if deleteErr := backend.Delete(ctx, filePath); deleteErr != nil {
 				logger.WarnF(ctx, "清理未写入数据库的上传对象失败: %v", deleteErr)
@@ -162,22 +161,22 @@ func loadUploadStats(ctx context.Context) ([]model.UploadStat, error) {
 
 var errUploadForbidden = errors.New("upload forbidden")
 
-func storeUploadObject(ctx context.Context, subPath string, size int64, mimeType string, buf *bytes.Buffer, meta *model.UploadMetadata) (string, string, error) {
+func storeUploadObject(ctx context.Context, subPath string, size int64, mimeType string, buf *bytes.Buffer, meta *model.UploadMetadata) (string, error) {
 	if uploadstorage.ReadOnly(ctx) {
-		return "", "", errors.New(shared.ErrStorageReadOnly)
+		return "", errors.New(shared.ErrStorageReadOnly)
 	}
 	driver, backend, err := storage.Active(ctx)
 	if err != nil {
 		logger.ErrorF(ctx, "初始化活动存储失败: %v", err)
-		return "", "", errors.New(shared.ErrSaveFileFailed)
+		return "", errors.New(shared.ErrSaveFileFailed)
 	}
 	result, err := backend.Put(ctx, subPath, bytes.NewReader(buf.Bytes()), size, mimeType)
 	if err != nil {
 		logger.ErrorF(ctx, "写入 %s 存储失败: %v", driver, err)
-		return "", "", errors.New(shared.ErrSaveFileFailed)
+		return "", errors.New(shared.ErrSaveFileFailed)
 	}
 	meta.Bucket = result.Bucket
-	return string(driver), result.Key, nil
+	return result.Key, nil
 }
 
 func validateUploadAllowedExtension(ctx context.Context, ext string) string {

internal/apps/upload/handler/routers.go

@@ -138,29 +138,28 @@ func UploadFile(c *gin.Context) {
 	id := idgen.NextUint64ID()
 	subPath := fmt.Sprintf("uploads/%s/%d.%s", time.Now().Format("2006/01/02"), id, ext)
 
-	storageDriver, subPath, err := storeUploadObject(ctx, subPath, size, mimeType, &buf, &meta)
+	subPath, err = storeUploadObject(ctx, subPath, size, mimeType, &buf, &meta)
 	if err != nil {
 		response.AbortBadRequest(c, err.Error())
 		return
 	}
 
 	newUpload := model.Upload{
-		ID:            id,
-		UserID:        currUser.ID,
-		FileName:      origName,
-		FilePath:      subPath,
-		FileSize:      size,
-		MimeType:      mimeType,
-		Extension:     ext,
-		Hash:          fileHash,
-		StorageDriver: storageDriver,
-		Type:          uploadType,
-		Status:        model.UploadStatusUsed,
-		AccessMode:    accessMode,
-		Metadata:      meta,
+		ID:         id,
+		UserID:     currUser.ID,
+		FileName:   origName,
+		FilePath:   subPath,
+		FileSize:   size,
+		MimeType:   mimeType,
+		Extension:  ext,
+		Hash:       fileHash,
+		Type:       uploadType,
+		Status:     model.UploadStatusUsed,
+		AccessMode: accessMode,
+		Metadata:   meta,
 	}
 
-	if err := saveNewUploadRecord(ctx, &newUpload, storageDriver, subPath); err != nil {
+	if err := saveNewUploadRecord(ctx, &newUpload, subPath); err != nil {
 		response.AbortBadRequest(c, shared.ErrSaveUploadRecordFailed)
 		return
 	}

internal/apps/upload/handler/routers_test.go

@@ -193,10 +193,6 @@ func TestUploadFile(t *testing.T) {
 			t.Errorf("incorrect mime type detected: %s", dbRecord.MimeType)
 		}
 
-		if dbRecord.StorageDriver != "s3" {
-			t.Errorf("expected storage driver s3, got %s", dbRecord.StorageDriver)
-		}
-
 		if dbRecord.Metadata.Extra["source"] != "test_runner" {
 			t.Errorf("expected extra meta 'source' to be 'test_runner', got %v", dbRecord.Metadata.Extra)
 		}
@@ -325,10 +321,6 @@ func TestUploadFile(t *testing.T) {
 			t.Fatalf("failed to unmarshal local upload record: %v", err)
 		}
 
-		if localRecord.StorageDriver != "local" {
-			t.Errorf("expected storage driver local, got %s", localRecord.StorageDriver)
-		}
-
 		// Confirm file was actually written to local disk
 		fileContent, err := os.ReadFile(localRecord.FilePath)
 		if err != nil {
@@ -358,7 +350,6 @@ func TestDownloadFile(t *testing.T) {
 		FileSize:      12,
 		MimeType:      "text/plain",
 		Extension:     "txt",
-		StorageDriver: "local",
 		Status:        model.UploadStatusUsed,
 	}
 
@@ -426,7 +417,6 @@ func TestListFiles(t *testing.T) {
 			FileSize:      10,
 			MimeType:      "text/plain",
 			Extension:     "txt",
-			StorageDriver: "local",
 			Status:        model.UploadStatusUsed,
 		},
 		{
@@ -437,7 +427,6 @@ func TestListFiles(t *testing.T) {
 			FileSize:      20,
 			MimeType:      "image/png",
 			Extension:     "png",
-			StorageDriver: "local",
 			Status:        model.UploadStatusUsed,
 		},
 		{
@@ -448,7 +437,6 @@ func TestListFiles(t *testing.T) {
 			FileSize:      30,
 			MimeType:      "text/markdown",
 			Extension:     "md",
-			StorageDriver: "local",
 			Status:        model.UploadStatusUsed,
 		},
 		{
@@ -459,7 +447,6 @@ func TestListFiles(t *testing.T) {
 			FileSize:      40,
 			MimeType:      "text/plain",
 			Extension:     "txt",
-			StorageDriver: "local",
 			Status:        model.UploadStatusUsed,
 		},
 	}
@@ -582,7 +569,6 @@ func TestBatchDownloadFiles(t *testing.T) {
 			FileSize:      13,
 			MimeType:      "text/plain",
 			Extension:     "txt",
-			StorageDriver: "local",
 			Status:        model.UploadStatusUsed,
 		},
 		{
@@ -593,7 +579,6 @@ func TestBatchDownloadFiles(t *testing.T) {
 			FileSize:      13,
 			MimeType:      "text/plain",
 			Extension:     "txt",
-			StorageDriver: "local",
 			Status:        model.UploadStatusUsed,
 		},
 		{
@@ -604,7 +589,6 @@ func TestBatchDownloadFiles(t *testing.T) {
 			FileSize:      28,
 			MimeType:      "text/plain",
 			Extension:     "txt",
-			StorageDriver: "local",
 			Status:        model.UploadStatusUsed,
 		},
 	}
@@ -773,7 +757,6 @@ func TestGetFileStats(t *testing.T) {
 			FileSize:      100,
 			MimeType:      "image/png",
 			Extension:     "png",
-			StorageDriver: "local",
 			Type:          "generic",
 			Status:        model.UploadStatusUsed,
 			CreatedAt:     time.Now(),
@@ -786,7 +769,6 @@ func TestGetFileStats(t *testing.T) {
 			FileSize:      500,
 			MimeType:      "video/mp4",
 			Extension:     "mp4",
-			StorageDriver: "local",
 			Type:          "generic",
 			Status:        model.UploadStatusUsed,
 			CreatedAt:     time.Now().AddDate(0, 0, -2), // 2 days ago
@@ -799,7 +781,6 @@ func TestGetFileStats(t *testing.T) {
 			FileSize:      200,
 			MimeType:      "application/pdf",
 			Extension:     "pdf",
-			StorageDriver: "local",
 			Type:          "avatar", // different type
 			Status:        model.UploadStatusUsed,
 			CreatedAt:     time.Now().AddDate(0, 0, -10), // older than 7 days
@@ -891,7 +872,6 @@ func TestUserUploadManagement(t *testing.T) {
 		FileSize:      100,
 		MimeType:      "text/plain",
 		Extension:     "txt",
-		StorageDriver: "local",
 		Status:        model.UploadStatusUsed,
 		CreatedAt:     time.Now(),
 	}
@@ -903,7 +883,6 @@ func TestUserUploadManagement(t *testing.T) {
 		FileSize:      200,
 		MimeType:      "image/png",
 		Extension:     "png",
-		StorageDriver: "local",
 		Status:        model.UploadStatusUsed,
 		CreatedAt:     time.Now(),
 	}