Add proxy endpoint to fix CORS issues for file previews

- Create new `/api/files/proxy-preview` endpoint that fetches and serves files directly
- Update FilePreviewModal to use proxy endpoint for images and PDFs
- Set appropriate headers for inline display and caching
- Remove trailing slash from folder display names in file list

server/api/files/list.ts

@@ -81,7 +81,7 @@ function getDisplayName(filepath: string): string {
   // Handle folders (ending with /)
   if (filepath.endsWith('/')) {
     const parts = filepath.slice(0, -1).split('/');
-    return parts[parts.length - 1] + '/';
+    return parts[parts.length - 1]; // Return folder name without trailing slash
   }
   
   // Get just the filename from the full path

server/api/files/proxy-preview.ts

@@ -0,0 +1,49 @@
+import { getDownloadUrl } from '~/server/utils/minio';
+import mime from 'mime-types';
+
+export default defineEventHandler(async (event) => {
+  try {
+    const query = getQuery(event);
+    const fileName = query.fileName as string;
+    
+    if (!fileName) {
+      throw createError({
+        statusCode: 400,
+        statusMessage: 'File name is required',
+      });
+    }
+    
+    // Get content type
+    const contentType = mime.lookup(fileName) || 'application/octet-stream';
+    
+    // Get the download URL
+    const url = await getDownloadUrl(fileName);
+    
+    // Fetch the file content from MinIO
+    const response = await fetch(url);
+    
+    if (!response.ok) {
+      throw createError({
+        statusCode: response.status,
+        statusMessage: 'Failed to fetch file from storage',
+      });
+    }
+    
+    // Get the file buffer
+    const buffer = Buffer.from(await response.arrayBuffer());
+    
+    // Set appropriate headers for preview
+    setHeader(event, 'Content-Type', contentType);
+    setHeader(event, 'Content-Disposition', 'inline');
+    setHeader(event, 'Cache-Control', 'public, max-age=3600');
+    
+    // Return the file buffer
+    return buffer;
+  } catch (error: any) {
+    console.error('Failed to proxy preview:', error);
+    throw createError({
+      statusCode: 500,
+      statusMessage: error.message || 'Failed to proxy preview',
+    });
+  }
+});