feat(file-preview): 增加PDF文件预览功能并优化预览逻辑

- 引入统一的文件预览工具函数和类型定义
- 添加PDF文件类型的识别和预览支持
- 使用iframe实现PDF文件在线预览
- 重构文件预览逻辑，统一处理不同文件类型的预览
- 优化文本内容预览的长度截取机制
- 更新预览按钮加载状态显示
- 统一预览窗口的最大高度配置
- 修改API调用路径为专门的预览接口

frontend/src/pages/DataManagement/Detail/useFilesOperation.ts

@@ -4,7 +4,12 @@ import type {
 } from "@/pages/DataManagement/dataset.model";
 import { App } from "antd";
 import { useState } from "react";
-import { PREVIEW_TEXT_MAX_LENGTH, resolvePreviewFileType, truncatePreviewText } from "@/utils/filePreview";
+import {
+  PREVIEW_TEXT_MAX_LENGTH,
+  resolvePreviewFileType,
+  truncatePreviewText,
+  type PreviewFileType,
+} from "@/utils/filePreview";
 import {
   deleteDatasetFileUsingDelete,
   downloadFileByIdUsingGet,
@@ -35,7 +40,7 @@ export function useFilesOperation(dataset: Dataset) {
   const [previewVisible, setPreviewVisible] = useState(false);
   const [previewContent, setPreviewContent] = useState("");
   const [previewFileName, setPreviewFileName] = useState("");
-  const [previewFileType, setPreviewFileType] = useState<"text" | "image" | "video" | "audio">("text");
+  const [previewFileType, setPreviewFileType] = useState<PreviewFileType>("text");
   const [previewMediaUrl, setPreviewMediaUrl] = useState("");
   const [previewLoading, setPreviewLoading] = useState(false);
 
@@ -111,7 +116,7 @@ export function useFilesOperation(dataset: Dataset) {
       return;
     }
 
-    const fileUrl = `/api/data-management/datasets/${datasetId}/files/${file.id}/download`;
+    const previewUrl = `/api/data-management/datasets/${datasetId}/files/${file.id}/preview`;
     setPreviewFileName(file.fileName);
     setPreviewFileType(fileType);
     setPreviewContent("");
@@ -120,7 +125,7 @@ export function useFilesOperation(dataset: Dataset) {
     if (fileType === "text") {
       setPreviewLoading(true);
       try {
-        const response = await fetch(fileUrl);
+        const response = await fetch(previewUrl);
         if (!response.ok) {
           throw new Error("下载失败");
         }
@@ -136,7 +141,7 @@ export function useFilesOperation(dataset: Dataset) {
       return;
     }
 
-    setPreviewMediaUrl(fileUrl);
+    setPreviewMediaUrl(previewUrl);
     setPreviewVisible(true);
   };