fix(canvas): 修复参考图像合并逻辑

- 修复了源引用图像与生成上下文图像的合并方式
- 当源引用存在时仅使用源引用图像，避免重复合并
- 确保图像编辑和生成类型的正确判断

web/src/app/(user)/canvas/[id]/canvas-client-page.tsx

@@ -1461,7 +1461,7 @@ function InfiniteCanvasPage() {
           const sourceReference = isImageNode && sourceNode?.metadata?.content
             ? [{ id: sourceNode.id, name: `${sourceNode.title || sourceNode.id}.png`, type: sourceNode.metadata.mimeType || "image/png", dataUrl: sourceNode.metadata.content, storageKey: sourceNode.metadata.storageKey }]
             : [];
-          const referenceImages = [...sourceReference, ...generationContext.referenceImages];
+          const referenceImages = sourceReference.length ? sourceReference : generationContext.referenceImages;
           const generationType = referenceImages.length ? "edit" as const : "generation" as const;
           const generationMetadata = buildImageGenerationMetadata(generationType, generationConfig, count, referenceImages);
           const parentConfig = NODE_DEFAULT_SIZE[isConfigNode ? CanvasNodeType.Config : isImageNode ? CanvasNodeType.Image : CanvasNodeType.Text];