VisBug should render in `:top-layer`

[FortyGazelle700]

When using the new browser dialog element, and call showModal() and trying to visually inspect an element using VisBug, VisBug appears underneath the top layer and get shown behind the modal, making it really hard to inspect modal elements using this extension.

[argyleink]

tooootally.

visbug needs to exist on :top-layer too so it can overlay these new elements that inhabit the top layer.

[hchiam]

i had a quick skim over https://stackoverflow.com/questions/75509725/place-an-element-above-the-top-layer and some of the links there.

HMW put VisBug in the :top-layer?

• somehow inject elements into the :top-layer?
• put things inside an invisible <dialog>, since <dialog>s can be stacked?

[argyleink]

my current thinking is: project needs to move to / experiment with popover, which will get put into the top layer, can stack on each other, etc. there's a polyfill for it too https://github.com/oddbird/popover-polyfill

[argyleink]

after that, it'd be nice to move to anchor() positioning too, but that spec is less stable and adopting it now would likely be premature.