feat: voice bubbles (WhatsApp-style chunked TTS) - #6

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Parameter 'idx' is declared but never used. Unused parameters should start with a '_'.

Parameter 'kv' is declared but never used. Unused parameters should start with a '_'.

Parameter 'options' is declared but never used. Unused parameters should start with a '_'.

Parameter 'url' is declared but never used. Unused parameters should start with a '_'.