[LocalMode] A/B voice comparison — two labeled columns, each with a language-grouped voice select (VoicePicker) and a native <audio> player shown once audio is set, a shared comparison textarea, and a Compare button with a loading state. Wire onCompare to two useSynthesizeSpeech runs and pass the resulting Blob
pnpm dlx shadcn@latest add "https://registry.directory/r/localmode-ai/ui/audio/voice-comparison-panel.json"