Replace the path+dropdown loader (and its non-rendering ui.gifs) with one
node mirroring FoleyTuneVideoLoaderUpload: a `video` upload widget with
drag-drop and an inline video preview, shipped via web/js/UniverSRVideo.js
(adapted from FoleyTuneVideo.js) + WEB_DIRECTORY.
The loader now outputs (UNIVERSR_VIDEO, AUDIO) so you can super-resolve the
audio and remux it. Updated the example workflow output order and README.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
