fix(Flyout): update z-indexes to temp values

[LinKCoding]

Overview

Raises temporary z-index values so Popover-related surfaces and toasts sit above Overlay (default z-index 3) until a shared scale lands in GM-624.

• Set BodyPortal zIndex={5} on Popover portal paths in Popover/elements.tsx (animated and non-animated)
• Set BodyPortal zIndex={5} on PopoverContainer when content is portaled
• Set BodyPortal zIndex={4} on Toaster
• Added a gamut patch version plan for the temporary z-index changes

PR Checklist

• Related to designs:
• Related to JIRA ticket: GMT-1720
• Version plan added/updated (or not needed)
• I have run this code to verify it works
• This PR includes unit tests for the code change
• This PR includes testing instructions tests for the code change
• The alpha package of this PR is passing end-to-end tests in all relevant Codecademy repositories

Testing Instructions

Don't make me tap the sign.

1. Go to Flyout, hover over the close button and see the tooltip appear
2. Go to the Toaster story; trigger a toast while an Overlay is visible and confirm the toast appears above the overlay.
3. Just in case, go to Popover and PopoverContainer; see that the rendering has the layers correct
4. Repeat the Popover / PopoverContainer / Toaster checks in dark mode and confirm stacking still looks correct.
5. Spot-check with VoiceOver that popover and toast content remains reachable/announced as before (no regression from the portal z-index change).
6. Finish and do a celebratory dance

PR Links and Envs

Repository	PR Link
Monolith	Monolith PR
Mono	Mono PR

[nx-cloud]

View your CI Pipeline Execution ↗ for commit 2b3d185

---

☁️ Nx Cloud last updated this comment at 2026-08-06 15:03:03 UTC

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.44%. Comparing base (8a6a54c) to head (2b3d185).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3403      +/-   ##
==========================================
- Coverage   90.86%   90.44%   -0.43%     
==========================================
  Files         403      275     -128     
  Lines        6681     5765     -916     
  Branches     2169     1947     -222     
==========================================
- Hits         6071     5214     -857     
+ Misses        601      542      -59     
  Partials        9        9              

Flag	Coverage Δ
main	?
pull-request	90.44% <100.00%> (?)

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[codecademydev]

📬 Published Alpha Packages:

Package	Version	npm	Diff
@codecademy/gamut	72.5.2-alpha.d72c03.0	npm	diff
@codecademy/gamut-icons	9.57.12-alpha.d72c03.0	npm	diff
@codecademy/gamut-illustrations	0.58.17-alpha.d72c03.0	npm	diff
@codecademy/gamut-kit	3.0.15-alpha.d72c03.0	npm	diff
@codecademy/gamut-patterns	0.10.36-alpha.d72c03.0	npm	diff
@codecademy/gamut-styles	20.1.1-alpha.d72c03.0	npm	diff
@codecademy/gamut-tests	6.0.7-alpha.d72c03.0	npm	diff
@codecademy/variance	0.26.2-alpha.d72c03.0	npm	diff
eslint-plugin-gamut	2.4.4-alpha.d72c03.0	npm	diff

[github-actions]

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