Extract UploadModal's storage+torrent upload core into a reusable
js/ui/components/mediaUploader.js (resolveActiveConnection, uploadThumbnail,
uploadVideo incl. infohash/.torrent/magnet) so the Edit modal can reuse it
without duplicating R2/S3 + torrent logic (and without blowing EditModal's
file-size budget). UploadModal now delegates its thumbnail/video upload core to
MediaUploader, keeping its own progress/state/zombie-guard wrappers — behavior
preserved.
UploadModal: 1319 -> 1191 lines. Build + full lint + unit suite green.
NOTE: the upload flow can't be unit-tested (browser + S3/R2 deps); this is a
behavior-preserving extraction pending manual re-test of a normal upload before
Edit upload is layered on top (steps 2-3).
Co-Authored-By: Claude Opus 4.8 <[email protected]>
