One-line: choose one of a known, short list — over ~10 options use Combobox so the user can type.

```jsx
<Field><Label htmlFor="tz">Time zone</Label>
  <Select id="tz" defaultValue="cet" items={[{value:"cet",label:"Europe/Berlin"},{value:"pst",label:"America/Los_Angeles"}]} />
</Field>
```

The trigger matches Input height for the same \`size\`. The popup is a standard Reckon popup: 10px radius, 1px border, faint large shadow, checkmark in a 16px gutter.
