[Luca Forstner (lforst)]

• Add initLogger({ attachmentStreamHook }) to transform captured LiveKit audio before upload. Previously, recordings were uploaded as raw PCM; hooks can now encode, filter, or omit audio and choose file boundaries.

  initLogger({
    projectName: "voice-agent",
    // New hook; this example passes captured audio through unchanged.
    attachmentStreamHook: async function* (source) {
      yield { format: source.format, chunks: source.chunks };
    },
  });

• Preserve recording timing and channel assignments across transformed files. If a hook fails, stop capture without uploading the original audio.

• Make flush() wait for pending recording uploads and closed streams to finish processing, so attachment references reach Braintrust before it returns.