Nothing reads defaults.max_playback_quality or defaults.max_profiles
anymore; new-user policy comes from groups and the only remaining
defaults.* consumer is defaults.card_overlays. Also extract role and
issuer-kind string constants flagged by goconst (presentation role
strings stay distinct from auth Permission values on purpose).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>