复用平台图标按钮收口参考图入口

编辑器生成输入框参考图按钮改为 PlatformIconButton surfaceFloating。

保留生成器局部尺寸和浅灰覆盖，避免重复维护图标按钮基础 chrome。

补充测试覆盖参考图按钮平台浮动按钮 class，并更新 TRACKING。

src/components/image-editor/ImageCanvasEditorView.tsx

@@ -69,6 +69,7 @@ import {
   PlatformFloatingMenu,
   PlatformFloatingMenuItem,
 } from '../common/PlatformFloatingMenu';
+import { PlatformIconButton } from '../common/PlatformIconButton';
 import { PlatformStatusMessage } from '../common/PlatformStatusMessage';
 import { UnifiedModal } from '../common/UnifiedModal';
 
@@ -2784,16 +2785,16 @@ export function ImageCanvasEditorView() {
                 }
               }}
             >
-              <button
-                type="button"
+              <PlatformIconButton
+                variant="surfaceFloating"
                 className="image-canvas-editor__generation-ref"
-                aria-label="添加参考图"
+                label="添加参考图"
                 disabled={generateDialog.status === 'generating'}
                 onClick={() => uploadInputRef.current?.click()}
+                icon={<ImageIcon className="h-4 w-4" />}
               >
-                <ImageIcon className="h-4 w-4" />
                 <span>参考图</span>
-              </button>
+              </PlatformIconButton>
               <textarea
                 aria-label="生成提示词"
                 value={generateDialog.prompt}