The push-to-talk capsule that anchors the mobile keyboard. 56px tall, full width.

```jsx
const { MicBar } = window.DuduDesignSystem_2e0172;
<MicBar state="idle" onPointerDown={start} onPointerUp={stop} />
<MicBar state="recording" />   // green + animated white waveform
<MicBar state="disabled" />    // 未登录
<MicBar state="quota" />       // 今日试用已用完 → 引导购买时长
```

Default copy is built in; override with `label`.
