First line: an underline tab bar with a terracotta active indicator and optional count pills.

```jsx
const [tab, setTab] = React.useState('chats');
<Tabs
  value={tab}
  onChange={setTab}
  items={[
    { id: 'chats', label: 'Чаты', count: 14 },
    { id: 'files', label: 'Файлы', count: 142 },
    { id: 'team',  label: 'Участники', count: 5 },
  ]}
/>
```

Notes
- Controlled — own the active `id` in state.
- Count pills tint terracotta on the active tab; omit `count` for plain tabs.