update App.tsx for embedding

src/App.tsx

@@ -286,6 +286,20 @@ function triggerBrowserDownload(href: string, fileName: string) {
   link.remove()
 }
 
+async function withAsyncTimeout<T>(promise: Promise<T>, timeoutMs: number, message: string): Promise<T> {
+  let timeoutHandle: ReturnType<typeof setTimeout> | null = null
+
+  const timeoutPromise = new Promise<T>((_, reject) => {
+    timeoutHandle = setTimeout(() => reject(new Error(message)), timeoutMs)
+  })
+
+  try {
+    return await Promise.race([promise, timeoutPromise])
+  } finally {
+    if (timeoutHandle) clearTimeout(timeoutHandle)
+  }
+}
+
 async function embedDownloadMetadata(blob: Blob, track: Track, details?: HydrusFileDetails | null, contentType?: string | null) {
   const metadata = buildHydrusDownloadMetadata(track, details)
   if (isMp3Download(track, details, contentType)) {
@@ -312,7 +326,11 @@ async function embedDownloadMetadata(blob: Blob, track: Track, details?: HydrusF
   if (!metadata.title && !metadata.artist && !metadata.album && !metadata.trackNumber) return { blob, note: undefined as string | undefined }
 
   try {
-    const taggedBlob = await embedContainerAudioMetadata(blob, getTrackExtension(track, details), metadata)
+    const taggedBlob = await withAsyncTimeout(
+      embedContainerAudioMetadata(blob, getTrackExtension(track, details), metadata),
+      15000,
+      'Metadata embedding timed out'
+    )
 
     return {
       blob: taggedBlob,
@@ -760,10 +778,19 @@ function App() {
           })
         }
 
-        updateDownload(id, {
-          note: 'Embedding metadata...',
-        })
-        const taggedDownload = await embedDownloadMetadata(blob, track, details, response.headers.get('content-type'))
+        const shouldEmbedMetadataClientSide = !isAppleMobileOrTablet
+        const taggedDownload = shouldEmbedMetadataClientSide
+          ? await (async () => {
+            updateDownload(id, {
+              note: 'Embedding metadata...',
+            })
+            return embedDownloadMetadata(blob, track, details, response.headers.get('content-type'))
+          })()
+          : {
+            blob,
+            note: 'iOS download: using server-provided metadata (client embedding skipped)',
+          }
+
         blob = taggedDownload.blob
         const downloadName = buildTrackDownloadName(track, details, response.headers.get('content-disposition'))
         const objectUrl = window.URL.createObjectURL(blob)
@@ -809,7 +836,7 @@ function App() {
         delete downloadAbortControllersRef.current[id]
       }
     })()
-  }, [downloads, updateDownload])
+  }, [downloads, isAppleMobileOrTablet, updateDownload])
 
   const cancelDownload = useCallback((id: string) => {
     const controller = downloadAbortControllersRef.current[id]