Settings → System → Career panel with the 'Crowd sound reactions' toggle
(writes the localStorage key the crowd layer reads). Pack manifests may
carry sfx {up, down} mp3s, validated like intro files.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Bundled plugin: per-song stars from best_accuracy (60/75/85% → 1/2/3★),
cumulative stars unlock bar → club → arena (data-driven venues.json).
Venue packs (UE-rendered crowd loops) download on demand to
CONFIG_DIR/plugin_uploads/career/ on a background thread with sha256 +
zip-slip validation, served via FileResponse. Career screen (promoted
sidebar entry) shows progress and pushes the active venue's manifest
into the crowd video layer (v3VenueCrowd, PR1) — degrades cleanly when
either side is absent. Pack URLs land in venues.json in PR3.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
