Discriminated-union JSON over three event types: play_started,
play_ended, play_skipped. Auth via existing RequireUser. play_started
returns play_event_id + session_id; the other two return { ok: true }.
Validates ownership: play_ended/play_skipped on another user's row
returns 403. Mount signature now takes EventsConfig and constructs
the playevents.Writer; server.New propagates it through.
Parses --config / SMARTMUSIC_CONFIG, loads YAML config with env overlay,
initializes slog, starts the chi HTTP server, and shuts down cleanly on
SIGINT/SIGTERM.
bvandeusen