diff --git a/.agent/skills/new-async-task/SKILL.md b/.agent/skills/new-async-task/SKILL.md
index 5305e14d..99f2b42e 100644
--- a/.agent/skills/new-async-task/SKILL.md
+++ b/.agent/skills/new-async-task/SKILL.md
@@ -43,7 +43,6 @@ description: "Wavelet 项目专用：新增或修改 Asynq 异步任务、后台
 - 失败返回 error，由任务框架处理状态和重试。
 - 不要吞掉关键错误。
 - 复杂 SQL 放到 `internal/model/` 或模块内的业务服务层（如 `internal/apps/<module>/service.go` 或 `logics.go`）。
-- 新增 Go 文件后检查许可证头，必要时运行 `make license`。
 
 ### 注册
 
diff --git a/frontend/app/(main)/admin/files/components/file-list.tsx b/frontend/app/(main)/admin/files/components/file-list.tsx
index aae424e4..fc217630 100644
--- a/frontend/app/(main)/admin/files/components/file-list.tsx
+++ b/frontend/app/(main)/admin/files/components/file-list.tsx
@@ -35,7 +35,8 @@ import {
   AlertDialogTitle,
 } from "@/components/ui/alert-dialog"
 import {Sheet, SheetContent, SheetDescription, SheetHeader, SheetTitle} from "@/components/ui/sheet"
-import services, {formatFileSize, getFileUrl} from "@/lib/services"
+import {FileImagePreview} from "@/components/common/file-image-preview"
+import services, {formatFileSize} from "@/lib/services"
 import type {Upload as UploadRecord} from "@/lib/services/upload/types"
 
 /* ─── 工具函数 ─────────────────────────────────────────── */
@@ -288,16 +289,12 @@ export function FileList() {
                     <TableCell className="py-3">
                       <div className="flex items-center justify-center size-9 rounded-lg bg-muted/40 overflow-hidden border">
                         {file.mime_type.startsWith("image/") ? (
-                          // eslint-disable-next-line @next/next/no-img-element
-                          <img
-                            src={getFileUrl(file.id, "low") ?? undefined}
+                          <FileImagePreview
+                            fileId={file.id}
                             alt={file.file_name}
-                            loading="lazy"
-                            decoding="async"
+                            quality="low"
+                            variant="compact"
                             className="size-full object-cover"
-                            onError={(e) => {
-                              ;(e.currentTarget as HTMLImageElement).style.display = "none"
-                            }}
                           />
                         ) : (
                           getFileIcon(file.mime_type, "size-4.5")
@@ -406,13 +403,12 @@ export function FileList() {
               {/* 大图/格式预览 */}
               <div className="flex items-center justify-center h-48 rounded-xl bg-muted/30 border border-dashed overflow-hidden p-2">
                 {detailTarget.mime_type.startsWith("image/") ? (
-                  // eslint-disable-next-line @next/next/no-img-element
-                  <img
-                    src={getFileUrl(detailTarget.id, "low") ?? undefined}
+                  <FileImagePreview
+                    fileId={detailTarget.id}
                     alt={detailTarget.file_name}
-                    loading="lazy"
-                    decoding="async"
+                    quality="low"
                     className="max-h-full max-w-full object-contain rounded-lg shadow-sm"
+                    fallbackClassName="min-h-32 w-full rounded-lg"
                   />
                 ) : (
                   <div className="flex flex-col items-center gap-3">
diff --git a/frontend/app/(main)/admin/files/components/storage-config-tab.tsx b/frontend/app/(main)/admin/files/components/storage-config-tab.tsx
index b6fdd5a0..29642f35 100644
--- a/frontend/app/(main)/admin/files/components/storage-config-tab.tsx
+++ b/frontend/app/(main)/admin/files/components/storage-config-tab.tsx
@@ -316,7 +316,7 @@ export function StorageConfigTab() {
         <CardFooter className="justify-end gap-2 flex-col sm:flex-row items-end sm:items-center border-t border-dashed pt-4 mt-6">
           {config.driver !== query.data?.config.driver && (
             <span className="text-xs text-amber-500 mr-auto text-left max-w-md">
-              ⚠️ 您已切换存储类型。请先点击“保存配置”保存各存储端的配置凭据，然后点击“开始迁移”手动执行文件迁移。
+              ⚠️ 您已切换存储类型。点击「保存配置」将立即切换活动存储引擎，并同步更新已有文件的存储驱动标记。仅在需要复制物理文件时才使用「开始迁移」。
             </span>
           )}
           <div className="flex gap-2">
diff --git a/frontend/components/common/file-image-preview.tsx b/frontend/components/common/file-image-preview.tsx
new file mode 100644
index 00000000..3564bca2
--- /dev/null
+++ b/frontend/components/common/file-image-preview.tsx
@@ -0,0 +1,62 @@
+"use client"
+
+import * as React from "react"
+import {ImageOff} from "lucide-react"
+
+import {cn} from "@/lib/utils"
+import {getFileUrl, type ImageQuality} from "@/lib/services/upload/utils"
+
+type FileImagePreviewProps = {
+  fileId: string | number
+  alt: string
+  quality?: ImageQuality
+  className?: string
+  fallbackClassName?: string
+  variant?: "compact" | "default"
+}
+
+export function FileImagePreview({
+  fileId,
+  alt,
+  quality = "low",
+  className,
+  fallbackClassName,
+  variant = "default",
+}: FileImagePreviewProps) {
+  const [failed, setFailed] = React.useState(false)
+  const src = getFileUrl(fileId, quality)
+
+  React.useEffect(() => {
+    setFailed(false)
+  }, [fileId, quality])
+
+  if (!src || failed) {
+    return (
+      <div
+        role="img"
+        aria-label={`${alt} 加载失败`}
+        className={cn(
+          "flex size-full flex-col items-center justify-center gap-1 bg-muted/50 text-muted-foreground",
+          fallbackClassName,
+        )}
+      >
+        <ImageOff className={cn("shrink-0 opacity-70", variant === "compact" ? "size-3.5" : "size-5")} />
+        {variant === "default" && (
+          <span className="text-[10px] leading-none">加载失败</span>
+        )}
+      </div>
+    )
+  }
+
+  return (
+    // eslint-disable-next-line @next/next/no-img-element
+    <img
+      src={src}
+      alt={alt}
+      loading="lazy"
+      decoding="async"
+      className={className}
+      onError={() => setFailed(true)}
+    />
+  )
+}
\ No newline at end of file
diff --git a/frontend/components/common/user/file-manager.tsx b/frontend/components/common/user/file-manager.tsx
index 8fe47601..15e94b49 100644
--- a/frontend/components/common/user/file-manager.tsx
+++ b/frontend/components/common/user/file-manager.tsx
@@ -1,23 +1,23 @@
 "use client"
 
 import * as React from "react"
-import {useQuery, useMutation, useQueryClient} from "@tanstack/react-query"
+import {useMutation, useQuery, useQueryClient} from "@tanstack/react-query"
 import {
-  Upload,
-  Trash2,
+  ChevronLeft,
+  ChevronRight,
   Download,
-  Search,
-  FileText,
-  FileImage,
-  FileVideo,
-  FileAudio,
   FileArchive,
-  Loader2,
+  FileAudio,
+  FileImage,
+  FileText,
+  FileVideo,
   Globe,
+  Loader2,
   Lock,
   Plus,
-  ChevronLeft,
-  ChevronRight
+  Search,
+  Trash2,
+  Upload
 } from "lucide-react"
 import {toast} from "sonner"
 
@@ -36,7 +36,8 @@ import {
   AlertDialogTitle,
 } from "@/components/ui/alert-dialog"
 
-import services, {formatFileSize, getFileUrl} from "@/lib/services"
+import {FileImagePreview} from "@/components/common/file-image-preview"
+import services, {formatFileSize} from "@/lib/services"
 import type {Upload as UploadRecord} from "@/lib/services/upload/types"
 
 /* ─── 工具函数 ─────────────────────────────────────────── */
@@ -238,16 +239,12 @@ export function UserFileManager() {
               {/* 文件预览/图标区 */}
               <div className="h-36 bg-muted/30 border-b border-dashed relative flex items-center justify-center overflow-hidden p-2 group-hover:bg-muted/10 transition-colors">
                 {file.mime_type.startsWith("image/") ? (
-                  // eslint-disable-next-line @next/next/no-img-element
-                  <img
-                    src={getFileUrl(file.id, "medium") ?? undefined}
+                  <FileImagePreview
+                    fileId={file.id}
                     alt={file.file_name}
-                    loading="lazy"
-                    decoding="async"
+                    quality="medium"
                     className="max-h-full max-w-full object-contain rounded-md shadow-xs transition-transform duration-350 group-hover:scale-103"
-                    onError={(e) => {
-                      ;(e.currentTarget as HTMLImageElement).style.display = "none"
-                    }}
+                    fallbackClassName="min-h-full w-full rounded-md"
                   />
                 ) : (
                   getFileIcon(file.mime_type)
@@ -283,7 +280,7 @@ export function UserFileManager() {
 
                 <div className="flex items-center justify-between pt-1 border-t border-dashed">
                   <span className="text-[9px] text-muted-foreground/80">{formatDate(file.created_at)}</span>
-                  
+
                   <div className="flex items-center gap-1">
                     <Button
                       size="icon"
diff --git a/internal/apps/admin/system_config/logics.go b/internal/apps/admin/system_config/logics.go
index 04630e82..f3e9d3a1 100644
--- a/internal/apps/admin/system_config/logics.go
+++ b/internal/apps/admin/system_config/logics.go
@@ -7,6 +7,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"time"
 
 	"github.com/Rain-kl/Wavelet/internal/db"
@@ -87,6 +88,9 @@ func updateSystemConfig(ctx context.Context, key string, req UpdateSystemConfigR
 		if err := tx.Model(&config).Updates(updates).Error; err != nil {
 			return err
 		}
+		if err := repointUploadStorageDriversOnDriverSwitch(ctx, tx, key, originalDriver, req.Value); err != nil {
+			return err
+		}
 		resolveStorageMigrationTasksOnDirectDriverUpdate(ctx, tx, key, originalDriver, req.Value)
 		return nil
 	}); err != nil {
@@ -97,6 +101,38 @@ func updateSystemConfig(ctx context.Context, key string, req UpdateSystemConfigR
 	return nil
 }
 
+func repointUploadStorageDriversOnDriverSwitch(
+	ctx context.Context,
+	tx *gorm.DB,
+	key string,
+	originalDriver storage.Driver,
+	newValue string,
+) error {
+	if key != model.ConfigKeyStorageConfig || originalDriver == "" {
+		return nil
+	}
+
+	var newCfg storage.Config
+	if err := json.Unmarshal([]byte(newValue), &newCfg); err != nil {
+		return fmt.Errorf("parse storage config for driver repoint: %w", err)
+	}
+	if newCfg.Driver == "" || newCfg.Driver == originalDriver {
+		return nil
+	}
+
+	result := tx.Model(&model.Upload{}).
+		Where("storage_driver = ? AND status != ?", string(originalDriver), model.UploadStatusDeleted).
+		Update("storage_driver", string(newCfg.Driver))
+	if result.Error != nil {
+		return result.Error
+	}
+	if result.RowsAffected > 0 {
+		logger.InfoF(ctx, "[StorageConfig] switched driver %s -> %s, repointed %d upload records",
+			originalDriver, newCfg.Driver, result.RowsAffected)
+	}
+	return nil
+}
+
 func resolveStorageMigrationTasksOnDirectDriverUpdate(
 	ctx context.Context,
 	tx *gorm.DB,
diff --git a/internal/apps/admin/system_config/routers.go b/internal/apps/admin/system_config/routers.go
index 6fdbc21f..5d87e247 100644
--- a/internal/apps/admin/system_config/routers.go
+++ b/internal/apps/admin/system_config/routers.go
@@ -310,10 +310,6 @@ func validateAndMergeStorageConfig(ctx context.Context, value string, currentCon
 	if err := validateMergedStorageConfig(ctx, currentCfg, newCfg, targetCfg); err != nil {
 		return "", err
 	}
-	if newCfg.Driver != "" && newCfg.Driver != currentCfg.Driver {
-		// 切换存储类型时仅暂存目标后端参数，活动 driver 由迁移任务正式切换。
-		targetCfg.Driver = currentCfg.Driver
-	}
 
 	// 序列化为最终保存的真实明文配置，防止保存屏蔽的 ****** 字符
 	unmaskedVal, err := json.Marshal(targetCfg)
diff --git a/internal/apps/admin/system_config/routers_test.go b/internal/apps/admin/system_config/routers_test.go
index b6e9270c..02e19948 100644
--- a/internal/apps/admin/system_config/routers_test.go
+++ b/internal/apps/admin/system_config/routers_test.go
@@ -441,7 +441,7 @@ func TestUpdateStorageConfigValidation(t *testing.T) {
 		}
 	})
 
-	t.Run("stage local config while active s3 is unreachable", func(t *testing.T) {
+	t.Run("switch to local while active s3 is unreachable", func(t *testing.T) {
 		activeCfg := storage.DefaultConfig()
 		activeCfg.Driver = storage.DriverS3
 		activeCfg.S3.Endpoint = "http://127.0.0.1:9999"
@@ -486,8 +486,8 @@ func TestUpdateStorageConfigValidation(t *testing.T) {
 		if err := json.Unmarshal([]byte(dbCfg.Value), &savedCfg); err != nil {
 			t.Fatalf("parse saved storage config failed: %v", err)
 		}
-		if savedCfg.Driver != storage.DriverS3 {
-			t.Fatalf("active driver = %q, want %q until migration completes", savedCfg.Driver, storage.DriverS3)
+		if savedCfg.Driver != storage.DriverLocal {
+			t.Fatalf("active driver = %q, want %q after save", savedCfg.Driver, storage.DriverLocal)
 		}
 		if savedCfg.Local.Root != tempDir {
 			t.Fatalf("staged local root = %q, want %q", savedCfg.Local.Root, tempDir)
diff --git a/internal/storage/storage.go b/internal/storage/storage.go
index f2e1de9f..9f1d03c3 100644
--- a/internal/storage/storage.go
+++ b/internal/storage/storage.go
@@ -168,10 +168,11 @@ func ForDriver(ctx context.Context, driver Driver) (Backend, error) {
 	if err != nil {
 		return nil, err
 	}
-	if cfg.Driver == driver {
-		return NewBackend(ctx, cfg, driver)
+	backend, err := NewBackend(ctx, cfg, driver)
+	if err != nil {
+		return nil, fmt.Errorf("storage configuration for driver %q is unavailable: %w", driver, err)
 	}
-	return nil, fmt.Errorf("storage configuration for driver %q is unavailable", driver)
+	return backend, nil
 }
 
 type functionBackend struct {