优化：多指交互

src/components/CanvasLabelImage.tsx

@@ -14,6 +14,8 @@ interface CanvasLabelImageProps {
   variableDefaults?: Record<string, string> | null;
   /** design=设计预览（空变量显示占位）；output=排版/打印（空值隐藏图形元素） */
   mode?: ContentResolveMode;
+  /** 渲染倍率，设计画布应传 MM_TO_PX * zoom 与显示尺寸 1:1 对齐 */
+  renderScale?: number;
 }
 
 export const CanvasLabelImage: React.FC<CanvasLabelImageProps> = ({
@@ -26,6 +28,7 @@ export const CanvasLabelImage: React.FC<CanvasLabelImageProps> = ({
   transparentBackground = false,
   variableDefaults = null,
   mode = 'design' as ContentResolveMode,
+  renderScale = 16,
 }) => {
   const [dataUrl, setDataUrl] = useState<string>('');
   const [initialLoading, setInitialLoading] = useState<boolean>(true);
@@ -46,6 +49,7 @@ export const CanvasLabelImage: React.FC<CanvasLabelImageProps> = ({
       transparentBackground,
       variableDefaults,
       mode,
+      scale: renderScale,
     })
       .then((url) => {
         if (active) {
@@ -61,7 +65,7 @@ export const CanvasLabelImage: React.FC<CanvasLabelImageProps> = ({
     return () => {
       active = false;
     };
-  }, [widthMm, heightMm, elementsKey, rowDataKey, rowIndex, showBorder, transparentBackground, mode, elements, variableDefaults]);
+  }, [widthMm, heightMm, elementsKey, rowDataKey, rowIndex, showBorder, transparentBackground, mode, renderScale, elements, variableDefaults]);
 
   if (initialLoading && !dataUrl) {
     return (
@@ -78,10 +82,8 @@ export const CanvasLabelImage: React.FC<CanvasLabelImageProps> = ({
     <img
       src={dataUrl}
       alt="Label Preview"
-      className="w-full h-full object-fill pointer-events-none select-none block"
+      className="block w-full h-full pointer-events-none select-none"
       style={{
-        width: '100%',
-        height: '100%',
         imageRendering: 'auto',
       }}
     />