applySavedPrefs() rebuilt state.filters without the `genre` key, so with
saved prefs restored from localStorage state.filters.genre was undefined.
Clicking Filters ran renderDrawer(), which indexes f.genre.includes(g)
whenever the library has >=1 genre -> TypeError, renderDrawer aborts, and
openDrawer never removes translate-x-full. The drawer stayed off-screen so
the menu appeared dead. Only triggered for users with saved prefs AND a
non-empty genre list, matching the intermittent report.
Carry genre: [] alongside the other session-only facets (mastery, match),
mirroring the default and clear-all shapes which already include it.
Also rename the visible "Stems (sloppak)" drawer label to "Stems (feedpak)"
to match the public format name used elsewhere in the UI.
Signed-off-by: topkoa <topkoa@gmail.com>