feat: add captions support for video uploads

- Enhanced video previews with `<track>` element for captions.

frontend/src/app/(dashboard)/upload/page.tsx

@@ -218,7 +218,9 @@ export default function UploadPage() {
 									<div className="relative rounded-lg overflow-hidden border bg-zinc-100 dark:bg-zinc-800">
 										<div className="relative h-[400px] w-full flex items-center justify-center">
 											{file?.type.startsWith("video/") ? (
-												<video src={preview} controls className="max-h-full max-w-full" />
+												<video src={preview} controls className="max-h-full max-w-full">
+													<track kind="captions" />
+												</video>
 											) : (
 												<NextImage
 													src={preview}