Model picker: the popup's "Transcription model" field takes any faster-whisper size or Hugging Face CTranslate2 repo id; sent with every /sync; the server validates the name (never a path), canonicalises aliases, downloads on a side thread while the old model keeps subtitling, swaps between windows, restarts sessions, keeps the other model's cue cache as <id>.<model>.cues.json, reports model/model_loading/model_error (+ /health lists downloaded models). Overlay shows "Loading model X…" / the error.
Font family: any installed font in front of the preset stack, with a live preview and an installed/not-found probe in the popup; sanitised before CSS.
Launcher update step (server/update.py): run.cmd/run.sh fast-forward a git checkout or fetch the newest release zip first; --no-update skips it.
Stale .part downloads that YouTube answers with 416 are discarded and downloaded afresh.
AMO listing package under docs/amo/ + publish-addon.cmd; homepage_url in the manifest; .amo-upload-uuid untracked.
Docs: README/AGENTS.md sections for all of the above, live streams marked Firefox-only, README/reviewer notes/privacy policy aligned with what 0.6.0 actually sends.
Tests: 290 server (from 190), 136 addon (from 73).