feat(desktop): import local Pocket voices

[johnmatthewtennant]

Context

Pocket TTS currently offers bundled reference voices. People also need a local, private way to add a voice without sending audio to a cloud service.

Summary

Add a Pocket voice import flow to Voice settings. Buzz opens the native file picker, decodes common audio formats in the reusable buzz-voice crate, canonicalizes the selected audio, stores it under a content-derived identity in app data, selects it, and lets the user delete it later.

Changes

• Accept WAV, M4A, MP3, FLAC, OGG, and AIFF files between 2 and 30 seconds, including multichannel sources.
• Decode and downmix accepted audio to canonical mono 32 kHz PCM16 WAV before hashing and storage.
• Store imported voices behind stable pocket:imported:<sha256> identities and content-addressed files.
• Keep absolute file paths inside the native process and expose only voice metadata to React.
• Include imported voices in Pocket preview and live huddle playback.
• Add Add voice and delete controls while preserving the bundled Pocket voice catalog.
• Fall back to Mary when the selected imported voice is deleted.
• Keep durable import, selection, and deletion successful when a live TTS worker acknowledgement is delayed.
• Preserve bundled voices when optional import metadata is unreadable and keep failed deletion retryable.

Related issue

None found.

Testing

Production decoding was exercised with WAV, M4A with AAC, MP3, FLAC, OGG Vorbis, and AIFF fixtures. Each format canonicalized to mono 32 kHz PCM16 WAV. Manual validation in the combined daily-driver build covered native-picker import, Preview, live-huddle playback, deletion, and Mary fallback.

Screenshots

The Voice settings card preserves the bundled Pocket catalog and adds the local Add voice action.

Reviewer-reproducible examples

Create common-format fixtures and run them through the production importer:

. ./bin/activate-hermit
fixtures="$(mktemp -d)"
ffmpeg -hide_banner -loglevel error -f lavfi -i "sine=frequency=220:duration=3" -ac 2 -ar 44100 "$fixtures/voice.wav"
ffmpeg -hide_banner -loglevel error -i "$fixtures/voice.wav" -c:a aac "$fixtures/voice.m4a"
ffmpeg -hide_banner -loglevel error -i "$fixtures/voice.wav" "$fixtures/voice.mp3"
ffmpeg -hide_banner -loglevel error -i "$fixtures/voice.wav" "$fixtures/voice.flac"
ffmpeg -hide_banner -loglevel error -i "$fixtures/voice.wav" -c:a libvorbis "$fixtures/voice.ogg"
ffmpeg -hide_banner -loglevel error -i "$fixtures/voice.wav" -c:a pcm_s16be "$fixtures/voice.aiff"
BUZZ_VOICE_IMPORT_TEST_DIR="$fixtures" \
  cargo test -p buzz-voice imports_common_audio_format_fixtures -- --ignored --nocapture

Exercise import persistence, synthesis, deletion, and bundled-voice fallback with an installed Pocket model:

BUZZ_POCKET_MODEL_DIR=/path/to/pocket-model-bundle \
  cargo test -p buzz-voice --test pocket_import_audio \
  objective_import_synthesis_delete_and_mary_fallback \
  -- --ignored --nocapture

Exercise the native-picker boundary, selection, preview dispatch, deletion, cancellation, and invalid-file states:

cd desktop
pnpm build:e2e
pnpm exec playwright test tests/e2e/voice-settings.spec.ts --project=smoke

[johnmatthewtennant]

🤖 ### Pocket voice import

The Voice settings card preserves the bundled Pocket voice catalog and adds the local Add voice action.