Module frontend/ts/public/audio

Audio domain public surface.

Responsibility:

• Audio analysis/feature extraction lifecycle.
• Stable “snapshot” state exposed to the rest of the app.

Non-responsibilities:

• Visualization/UI.
• Device selection UX.

Start here:

• AudioEngine
• MusicFeatureExtractor
• createMusicFeatureExtractor

Invariants:

• Consumers treat state/feature outputs as "latest" readings sampled each frame.