Focus trap action/component

[techniq]

• https://css-tricks.com/a-css-approach-to-trap-focus-inside-of-an-element/
• https://www.npmjs.com/package/focus-svelte
• https://github.com/tailwindlabs/headlessui/blob/main/packages/@headlessui-react/src/components/focus-trap/focus-trap.tsx
• https://github.com/rgossiaux/svelte-headlessui/blob/master/src/lib/components/focus-trap/FocusTrap.svelte
• https://github.com/skeletonlabs/skeleton/blob/master/src/lib/actions/FocusTrap/focusTrap.ts
• https://mantine.dev/hooks/use-focus-trap/

Might also use dialog.showModal although Safari support is 15.4+