Mirror the upload-modal external-URL webseed for the Edit modal: when the user
changes a video's URL to an external link with no magnet, auto-derive the webseed
torrent (fetch + hash the remote file → magnet ws=url) so an edited external URL
keeps the P2P benefit. Best-effort + size-capped; on CORS / too-large / any error
it stays URL-only. Runs before the existing magnet normalization so the derived
magnet's ws/xs are extracted the same way a pasted magnet's are.
submit() is now async (it was fire-and-forget from the form handler; the
pendingSubmit guard already prevents re-entry, so it just stays "pending" during
the derivation).
Known gap: hosting the tiny .torrent (xs=) on the edit path needs storage-
credential plumbing the Edit modal doesn't currently have — so the edit path is
ws=-only for now (upload path hosts xs= when storage is unlocked). Tracked as a
follow-up.
Edit-modal submit-state + upload-field tests green. Lint + build green.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
