Snapshot the three public surfaces the audio-engine decomposition must not
change (docs/audio-engine-tlc.md Part IV §4): addon export table, audio-bridge
IPC channels, preload audio/audioEffects API keys. contract-check.test.js
diffs regenerated surfaces against the committed snapshots.
result-shapes.json (golden result key/type shapes) is deferred until the
engine_units harness can run the addon against a null device.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>