feat(ui): safe clipboard handling

[psychedelicious]

Summary

The clipboard API is not available by default on firefox. Until now, we have sometimes ignored (resulting in errors when a FF user attempts to copy something) and sometimes checked for access first. This PR refactors clipboard access across the UI to ensure it cannot cause errors.

The useClipboard hook exposes a boolean indicating if clipboard is available and provides a wrapper around the clipboard API.

The wrapper methods first check if clipboard access is available before attempting to copy to it. If not, a toast is displayed, linking to the new FAQ entry:

When clipboard access is available, there is no change to behaviour.

An eslint rule now prevents direct access to navigator.clipboard and points devs to the safe wrapper.

Related Issues / Discussions

One report for a copy feature that, via a happy code accident, handled errors from the clipboard API:
https://discord.com/channels/1020123559063990373/1149506274971631688/1337165581131972751

Been a number of issues over time, but I'm not sure if there are tickets for any of them.

QA Instructions

Follow the instructions in the new FAQ entry to disable clipboard on Firefox. You'll need to check the code in this PR for the instructions bc the docs link in the toast won't work until this is merged.

Attempt to copy an image via right-click or canvas. You should get the toast.

Enable clipboard, refresh the page and try again. Should work.

Merge Plan

Should go into v5.6.1

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Tests added / updated (if applicable)
• Documentation added / updated (if applicable)
• Updated What's New copy (if doing a release after this PR)