🐛 fix(word-preview): 修复图片字段处理错误

- 添加fileToBase64辅助函数，将图片文件转换为base64格式
- 修改图片字段处理逻辑，使用base64数据替代原始File对象
- 添加图片转换错误捕获和日志输出，提高代码健壮性

src/client/admin-shadcn/pages/WordPreview.tsx

@@ -222,6 +222,16 @@ export default function WordPreview() {
     return mimeTypes[extension || ''] || 'image/jpeg';
   };
 
+  // File转Base64的辅助函数
+  const fileToBase64 = (file: File): Promise<string> => {
+    return new Promise((resolve, reject) => {
+      const reader = new FileReader();
+      reader.onload = () => resolve(reader.result as string);
+      reader.onerror = reject;
+      reader.readAsDataURL(file);
+    });
+  };
+
   // 替换Word字段并插入图片
   const replaceFieldsInWord = async (wordFile: File, excelRow: ExcelRow, rowIndex: number): Promise<Blob> => {
     try {
@@ -253,16 +263,21 @@ export default function WordPreview() {
         }
       });
 
-      // 处理图片字段
+      // 处理图片字段 - 修复为base64格式
       const folderIndex = (rowIndex + 1).toString();
       if (imageMappings[folderIndex]) {
-        Object.entries(imageMappings[folderIndex]).forEach(([imageName, imageFile]) => {
-          processedData[`image:${imageName}`] = {
-            data: imageFile,
-            width: 200,
-            height: 150
-          };
-        });
+        for (const [imageName, imageFile] of Object.entries(imageMappings[folderIndex])) {
+          try {
+            const base64Data = await fileToBase64(imageFile);
+            processedData[`image:${imageName}`] = {
+              data: base64Data,
+              width: 200,
+              height: 150
+            };
+          } catch (error) {
+            console.error(`转换图片失败: ${imageName}`, error);
+          }
+        }
       }
 
       doc.setData(processedData);