This endpoint generates a short-lived Vercel Blob client token for direct uploads. Upload the file with the returned pathname and clientToken, then call /media/create to register the uploaded blob as media in your organization.Upload flow:
Call /media/create/url with the filename and optional MIME type
Upload the file directly to Vercel Blob using put(pathname, file, { token: clientToken })
Call /media/create with the uploaded blob URL to create the media record