fix(audio): preserve causes and use portable padding (#2769)

* fix(audio): preserve causes and use portable padding

* fix(audio): address failure taxonomy review

packages/engine/src/index.ts

@@ -198,8 +198,12 @@ export {
 export { createVideoFrameInjector } from "./services/videoFrameInjector.js";
 
 export { parseAudioElements, processCompositionAudio } from "./services/audioMixer.js";
+export { cloneCaptureWarning, cloneCaptureWarnings } from "./services/captureWarning.js";
 export type {
   AudioElement,
+  AudioFailureReason,
+  AudioFailureStage,
+  AudioProcessingFailure,
   AudioTrack,
   AudioVolumeKeyframe,
   MixResult,