Ember

Describe the bug
In Firefox, the zoom feature uses transform styles (see storybookjs/storybook#12845) - unfortunately this breaks positioning on elements that require position: fixed when in the "Docs" view.

Normally a position: fixed element's position would correspond to the viewport but in Firefox it corresponds to the element with the transform style.

Issue Summary

When setting up a dev env on windows, yarn setup fails

[2021-12-21 15:45:01] INFO Relation: User to Role                                                                              
[2021-12-21 15:45:01] INFO Finished database init!                                                                             
Running "symlink:githooks" (symlink) task               

By default ember-cli updates a number of the "app trees" to be from tests/dummy when developing an addon locally. We do this for app, styles, templates, public, and tests trees (handled inside lib/broccoli/ember-addon.js).

Unfortunately, we do not forward the apps vendor tree to tests/dummy/. This means that our addon's treeForVendor is called, but then subsequently clobbered by the "apps

Relevant conversation here: hjdivad/ember-m3#807

Breaking docs app is way too easy. See #1700 as a recent example. I think we should add some basic regressions tests. Most of the issues we have seen in the past would have be caught by a test, which simply tries to build the docs app. Maybe running yarn docs:build in CI is good enough as a starter.