Scans MUSIC_DIR (mounted at /music in Docker) with music-metadata to read embedded BPM/genre tags and classify tracks as upbeat/cinematic/ dreamy. Falls back to untagged general pool when mood bucket is thin. Slideshow plays real audio via <audio> element with range-request streaming; Web Audio synth is kept as fallback when MUSIC_DIR is unset. Shows now-playing title/artist in the slideshow bottom bar. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>