fix: display errors when adding a new repo

[andypols]

Summary

This PR fixes a bug where the client silently ignored server-side errors when adding a new repository. As a result, users were led to believe the repository was added successfully, only to see it disappear upon refreshing the page.

Root Cause

The NewRepo.tsx component (src/ui/views/RepoList/Components/NewRepo.tsx) always closed the modal, regardless of whether the server request succeeded or failed.

Fix

Display server errors returned by addRepo in src/ui/services/repo.js.

Extended Cypress tests to:

• Reproduce the bug.
• Verify the fix.
• Upgraded Cypress to version 14.5.2.
• Added data-testid attributes to improve selector stability in Cypress tests (avoids coupling to CSS/JS changes). These are are also useful in the react unit tests (see note)
• added a regular (non-admin) user for the cypress tests.
• added cypress tests to ensure anonymous and regular users cannot add a repository.
• added a cypress test to ensure an admin can successfully add and delete a repository.
• added a cypress tests that displays an error if tries to add a duplicate repository.

Notes

Adding unit tests for the React components is desirable but considered out of scope for this PR.

[netlify]

✅ Deploy Preview for endearing-brigadeiros-63f9d0 canceled.

Name	Link
🔨 Latest commit	33a5995
🔍 Latest deploy log	https://app.netlify.com/projects/endearing-brigadeiros-63f9d0/deploys/68b040e78158180008bcc3cb

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.84%. Comparing base (4bf2276) to head (33a5995).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1120      +/-   ##
==========================================
+ Coverage   82.83%   82.84%   +0.01%     
==========================================
  Files          66       66              
  Lines        2784     2787       +3     
  Branches      334      334              
==========================================
+ Hits         2306     2309       +3     
  Misses        431      431              
  Partials       47       47              

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[jescalada]

@andypols Looks great, thanks for the contribution! 🚀

Our E2E tests are pretty barebones so any improvements here are much appreciated! I just have some minor things to point out - will likely open a few issues for these!

[kriswest]

Needs a rebase, there are a handful of conflicting/similar changes in main.

I think there are some other cases where the errors aren't displayed that would benefit from similar changes, such as cancelling a push in the dashboard when you are not allowed. That's no doubt a separate issue ;-)

[kriswest]

LGTM - couple of minor comments.

The data-testid tags might be worth noting in the testing guide @jescalada is working on in #1147