fix: 场景裂变页面保留顶部工具栏

- 修改 ImageAnnotator 布局，使顶部工具栏在场景裂变模式下始终可见
- 将 SceneFusionView 嵌入到工具栏下方的工作区
- 隐藏 SceneFusionView 自带的顶部标题栏
- 优化场景裂变按钮的交互逻辑

components/image-annotator.tsx

@@ -1216,15 +1216,7 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
       className="fixed inset-0 z-[9999] flex items-center justify-center bg-background"
       onClick={onCancel}
     >
-      {showSceneFusion ? (
-        <div 
-          className="w-full h-full bg-background"
-          onClick={(e) => e.stopPropagation()}
-        >
-          <SceneFusionView onBack={() => setShowSceneFusion(false)} />
-        </div>
-      ) : (
-      /* 弹窗容器 - 全屏显示 */
+      {/* 弹窗容器 - 全屏显示 */}
       <div 
         className="flex flex-col overflow-hidden w-full h-full"
         onClick={(e) => e.stopPropagation()}
@@ -1254,7 +1246,7 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
               variant="ghost" 
               size="sm" 
               onClick={handleRemoveBackground} 
-              disabled={isRemovingBg || isEnhancing || isExtending || isResizeMode || showAngleEditDialog || !image}
+              disabled={isRemovingBg || isEnhancing || isExtending || isResizeMode || showAngleEditDialog || showSceneFusion || !image}
               title="移除背景（抠图）"
             >
               <Scissors className={`mr-1 h-4 w-4 ${isRemovingBg ? "animate-spin" : ""}`} />
@@ -1264,7 +1256,7 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
               variant="ghost" 
               size="sm" 
               onClick={handleEnhance} 
-              disabled={isEnhancing || isRemovingBg || isExtending || isResizeMode || showAngleEditDialog || !image}
+              disabled={isEnhancing || isRemovingBg || isExtending || isResizeMode || showAngleEditDialog || showSceneFusion || !image}
               title="图片变清晰"
             >
               <Sparkles className={`mr-1 h-4 w-4 ${isEnhancing ? "animate-spin" : ""}`} />
@@ -1274,7 +1266,7 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
               variant="ghost" 
               size="sm" 
               onClick={handleExtend} 
-              disabled={isExtending || isRemovingBg || isEnhancing || isResizeMode || showAngleEditDialog || !image}
+              disabled={isExtending || isRemovingBg || isEnhancing || isResizeMode || showAngleEditDialog || showSceneFusion || !image}
               title="图像拓展"
             >
               <Expand className={`mr-1 h-4 w-4 ${isExtending ? "animate-spin" : ""}`} />
@@ -1284,7 +1276,7 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
               variant="ghost" 
               size="sm" 
               onClick={handleResize} 
-              disabled={isResizeMode || isRemovingBg || isEnhancing || isExtending || showAngleEditDialog || !image}
+              disabled={isResizeMode || isRemovingBg || isEnhancing || isExtending || showAngleEditDialog || showSceneFusion || !image}
               title="尺寸调整"
             >
               <Maximize2 className="mr-1 h-4 w-4" />
@@ -1294,45 +1286,64 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
               variant="ghost" 
               size="sm" 
               onClick={handleAngleEdit} 
-              disabled={showAngleEditDialog || isRemovingBg || isEnhancing || isExtending || isResizeMode || !image}
+              disabled={showAngleEditDialog || isRemovingBg || isEnhancing || isExtending || isResizeMode || showSceneFusion || !image}
               title="角度调整"
             >
               <Move3D className="mr-1 h-4 w-4" />
               角度调整
             </Button>
             <Button 
-              variant="ghost" 
+              variant={showSceneFusion ? "secondary" : "ghost"}
               size="sm" 
-              onClick={() => setShowSceneFusion(true)} 
-              disabled={showSceneFusion || showAngleEditDialog || isRemovingBg || isEnhancing || isExtending || isResizeMode}
+              onClick={() => {
+                setShowSceneFusion(!showSceneFusion);
+                // 进入场景裂变时，退出其他模式
+                if (!showSceneFusion) {
+                  setIsResizeMode(false);
+                  setShowAngleEditDialog(false);
+                }
+              }} 
+              disabled={showAngleEditDialog || isRemovingBg || isEnhancing || isExtending || isResizeMode}
               title="场景裂变"
             >
               <Layers className="mr-1 h-4 w-4" />
               场景裂变
             </Button>
-            <Button variant="ghost" size="sm" onClick={handleUndo} disabled={actions.length === 0}>
-              <Undo className="mr-1 h-4 w-4" />
-              撤销
-            </Button>
-            <Button variant="ghost" size="sm" onClick={handleClear} disabled={actions.length === 0}>
-              <Trash2 className="mr-1 h-4 w-4" />
-              清空
-            </Button>
+            {!showSceneFusion && (
+              <>
+                <Button variant="ghost" size="sm" onClick={handleUndo} disabled={actions.length === 0}>
+                  <Undo className="mr-1 h-4 w-4" />
+                  撤销
+                </Button>
+                <Button variant="ghost" size="sm" onClick={handleClear} disabled={actions.length === 0}>
+                  <Trash2 className="mr-1 h-4 w-4" />
+                  清空
+                </Button>
+              </>
+            )}
             <Button variant="ghost" size="sm" onClick={onCancel}>
               <X className="mr-1 h-4 w-4" />
               取消
             </Button>
-            <Button size="sm" onClick={handleConfirm} className="bg-primary text-primary-foreground hover:bg-primary/90">
-              <Check className="mr-1 h-4 w-4" />
-              发送到新对话
-            </Button>
+            {!showSceneFusion && (
+              <Button size="sm" onClick={handleConfirm} className="bg-primary text-primary-foreground hover:bg-primary/90">
+                <Check className="mr-1 h-4 w-4" />
+                发送到新对话
+              </Button>
+            )}
           </div>
         </div>
 
-        {/* 工具选择栏 / 尺寸调整工具栏 */}
-        {isResizeMode ? (
-          /* 尺寸调整模式下显示尺寸调整工具栏 */
-          <div className="flex flex-col gap-3 border-b px-4 py-3 bg-muted/30">
+        {showSceneFusion ? (
+          <div className="flex-1 overflow-hidden relative">
+            <SceneFusionView onBack={() => setShowSceneFusion(false)} />
+          </div>
+        ) : (
+          <>
+            {/* 工具选择栏 / 尺寸调整工具栏 */}
+            {isResizeMode ? (
+              /* 尺寸调整模式下显示尺寸调整工具栏 */
+              <div className="flex flex-col gap-3 border-b px-4 py-3 bg-muted/30">
             {/* 比例选择和尺寸输入在同一行 */}
             <div className="flex items-center gap-4 flex-wrap">
               {/* 比例选择 */}
@@ -1708,8 +1719,9 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
             </>
           )}
         </div>
+          </>
+        )}
       </div>
-      )}
 
       {/* 文字输入弹窗 */}
       {textPosition && (

components/scene-fusion-view.tsx

@@ -304,7 +304,8 @@ export function SceneFusionView({ onBack }: SceneFusionViewProps) {
 
   return (
     <div className="flex flex-col w-full h-full bg-background">
-      {/* 顶部标题栏 */}
+      {/* 顶部标题栏 - 已在外部显示，此处隐藏 */
+      /*
       <div className="flex items-center justify-between border-b px-4 py-3 shrink-0">
         <div className="flex items-center gap-2">
           <Button variant="ghost" size="icon" onClick={onBack} title="返回图片编辑">
@@ -318,8 +319,9 @@ export function SceneFusionView({ onBack }: SceneFusionViewProps) {
         <div className="text-sm text-muted-foreground hidden md:block">
           上传1张产品图和多张场景图，AI 自动将产品融合到所有场景中
         </div>
-        <div className="w-10"></div>{/* 占位，保持标题居中 */}
+        <div className="w-10"></div>
       </div>
+      */}
 
       <div className="flex-1 overflow-hidden flex flex-col md:flex-row">
         {/* 左侧：输入区域 */}