- Move sound catalog registration off PageScene mount and into a single
SoundManager.install() call in GlobalSettingsManager so sounds exist at
app boot (previously silent until PageScene mounted).
- Honor the play_sounds master toggle in all five event playback sites
via SoundManager.playEvent helpers. Settings preview keeps firing
regardless (handled by SoundManager.playPreview).
- Replace per-callsite GetAppPreferences + SoundRegistry boilerplate in
the four generation event hooks and the file-deleted handler with
one-line SoundManager.* calls.
- Dedupe SOUND_OPTIONS: AudioSettingsPane now reads SoundManager.OPTIONS,
derived from a single declarative SOUNDS array (label-bearing entries
are user-selectable; others are still registered for code-driven use).
- Narrow the soundboard public barrel to SoundManager + SoundOption only;
SoundRegistry and SoundEffect are now lib-internal.