[popups] Select inputs on focus

[vladmoroz]

Migrating Paper from Radix to Base UI, I expected that input contents would be selected when popups are opened:

Radix Popover:

Screen.Recording.2025-03-02.at.17.46.30.mov

Base UI Popover:

Screen.Recording.2025-03-02.at.17.46.48.mov

---

As another example, native dialogs do the same:

Screen.Recording.2025-03-02.at.17.52.35.mov

[atomiks]

Workaround for now can be to manually select it with a ref inside a rAF upon open (to avoid scroll page jump, once the popup is positioned):

requestAnimationFrame(() => {
  inputRef.current.select();
});

[colmtuite]

Working on this @vladmoroz. Thanks 🙏