feat: lite mode (KLONKT_AUDIO=off) — audio disabled, single codebase
Boot flag that skips the entire audio feature: no audio/playlist/download/
embed routes (no ffmpeg calls), no tracks loaded, own-audio shortcodes
(track/album/playlist) stripped, audio buttons in admin/profile
hidden. Hub and Circles keep working; external embeds (YouTube/SoundCloud/
Spotify) keep working too. Default = on (full version unchanged).
This lets Klonkt run as a lightweight blog/photo/EPK site on an environment
without ffmpeg.
Co-Authored-By: Claude <noreply@…>