[Feature Request] Support Video (MP4/WebM) for Publication Preview

[CalaW]

Have you checked that your feature request isn't already filed?

• I read through FAQ and searched through the past issues, none of which addressed my feature request.
• Yes, I have checked that this feature request isn't already filed.

Description & Motivation

Currently, the publication preview in the al-folio template supports static images and animated images (e.g., GIF and animated WebP). However, these formats are not very efficient for longer or higher-resolution animations.
It would be very helpful if the template could support embedding short videos (e.g., MP4 or WebM) as publication previews. This would allow authors to replace GIFs with modern video formats that are significantly smaller and higher quality.

Pitch

Support video files (e.g., MP4/WebM) as publication previews.

For example, in _bibliography/papers.bib:

preview = {preview.mp4},

If the preview file is a video, the template could render a <video> element instead of an <img>, allowing authors to use efficient video formats instead of large animated GIF/WebP files.

Alternatives

There's already GIF and WebP animated image support in the template.

Additional context

N/A