An MV3 service worker is killed after ~30 s of idle time, so parking the
recording buffer in background memory (pending + 10-min auto-save timer)
was unreliable: the timer never fired and Save could hit a restarted
worker with an empty buffer. Now recorderStop uploads the media, submits
the report with the auto-title right away, and only then opens the
composer. Save patches title/description (PATCH /api/reports/{token}),
Discard deletes the report — both are token-based and survive worker
restarts. recorder_submit is replaced by recorder_edit/recorder_discard
{token}.

Co-Authored-By: Claude Code <noreply@anthropic.com>

- Popup: project dropdown (list_projects + settings_save defaultProjectId);
  switching refreshes the last-report card and panel link immediately.
- Recording stop no longer submits blindly: the buffer goes pending and a
  composer opens in the tab with title (prefilled) + description, Save
  (Ctrl+Enter, copies the share link) or two-step Discard; unanswered
  pending recordings auto-save after 10 minutes, and starting a new
  recording auto-saves a pending one. Composer survives navigation.
- WebM is now a square cursor-following crop (shared cursorCropRect helper
  with the GIF path), source dimension raised to 1280 so the 512px crop is
  native-resolution at DPR 1; full-frame 800px stays as fallback.
- e2e: second project + popup switcher asserts, composer save (typed
  title/description verified on server), keyboard-driven discard flow,
  ffprobe square-video assertions (512x512 VP8).

Co-Authored-By: Claude Code <noreply@anthropic.com>