Fix file downloads for Safari with proper filename handling

Implement browser-specific download methods to ensure files download with correct filenames across all browsers. Safari now uses window.location.href while other browsers use blob URLs. Add Content-Disposition header to proxy endpoint for proper filename preservation.

components/FilePreviewModal.vue

@@ -199,33 +199,51 @@ const handlePreviewError = (event: any) => {
   loading.value = false;
 };
 
-// Download file
+// Download file (with special handling for Safari)
 const downloadFile = async () => {
   if (!props.file) return;
   
   try {
-    // Use proxy download endpoint for better mobile compatibility
-    const proxyUrl = `/api/files/proxy-download?fileName=${encodeURIComponent(props.file.name)}`;
-    
-    // Create a link element
-    const link = document.createElement('a');
-    link.href = proxyUrl;
-    
     // Extract clean filename for download
     let filename = props.file.displayName;
     if (!filename.includes('.') && props.file.extension) {
       filename += '.' + props.file.extension;
     }
     
-    link.download = filename;
-    link.style.display = 'none';
-    document.body.appendChild(link);
-    link.click();
+    // Check if Safari (iOS or desktop)
+    const isSafari = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);
     
-    // Clean up
-    setTimeout(() => {
-      document.body.removeChild(link);
-    }, 100);
+    if (isSafari) {
+      // For Safari, use location.href to force proper filename handling
+      const downloadUrl = `/api/files/proxy-download?fileName=${encodeURIComponent(props.file.name)}`;
+      window.location.href = downloadUrl;
+    } else {
+      // For other browsers, use blob approach
+      const response = await fetch(`/api/files/proxy-download?fileName=${encodeURIComponent(props.file.name)}`);
+      
+      if (!response.ok) {
+        throw new Error('Failed to download file');
+      }
+      
+      const blob = await response.blob();
+      
+      // Create object URL from blob
+      const downloadUrl = URL.createObjectURL(blob);
+      
+      // Create a link element
+      const link = document.createElement('a');
+      link.href = downloadUrl;
+      link.download = filename;
+      link.style.display = 'none';
+      document.body.appendChild(link);
+      link.click();
+      
+      // Clean up
+      setTimeout(() => {
+        document.body.removeChild(link);
+        URL.revokeObjectURL(downloadUrl);
+      }, 100);
+    }
   } catch (err) {
     console.error('Failed to download file:', err);
   }