useUpload() does not forward the controller's retryUpload, so hosts cannot retry a single failed file

[BSalaeddin]

Found while adding per-file retry to a failed upload tile in a host app (@upupjs/react 3.2.0, re-exported verbatim by @upupjs/next).

What exists internally

• The controller implements retryUpload(fileId) (dist/index.js ~L3741) and puts it on the context as providerValues.upload.retryUpload (~L3897).
• useUploaderUploadControls() exposes upload.retryUpload; the vendor's own upup-retry-btn calls it (~L2506).

What a host can reach

• UploaderRef (index.d.ts L8) is { useUpload() } → { error, files, loading, progress, upload, resetState, uploadFiles, setFiles, replaceFiles }. No retryUpload, no core, no on.
• useUpload() (~L3944) receives the controller's retryUpload but forwards only startUpload.
• useUploaderUploadControls() resolves only inside UploaderContextProvider, and <UpupUploader> renders fixed children (no children prop), so a host cannot mount anything inside the provider.
• onError is (message: string) => void: no per-file error callback. FileUploadResult{status:'failed', error} and the 'upload-error': {error, file?} core event are only readable through the headless core/on, i.e. by abandoning the visual uploader.

Ask
Forward retryUpload from useUpload() (one line) so UploaderRef.useUpload().retryUpload(fileId) works, and/or add a per-file failure callback (onFileUploadError?: (file: File, error: string) => void) next to onFileUploadStart/onFileUploadComplete.

Workaround shipped on the host side meanwhile: keep the raw File from onFileUploadStart and re-enter it through initialFiles → uploadFiles, re-keying the tile by File identity because a fresh core assigns a new id.