[CI] Upload frontend unit and Playwright reports as workflow artifacts

[utksh1]

Summary

Frontend test failures are easier to debug when reports are preserved as artifacts, but the current workflow does not surface them prominently.

Scope

• Upload relevant frontend/unit and Playwright artifacts on failure (or always, if justified).
• Keep artifact retention reasonable.
• Avoid bloating the repo with generated files.

Acceptance criteria

• Useful frontend test artifacts are available from CI runs.
• The workflow does not encourage committing generated reports.
• Artifact retention is documented or obvious from the workflow.

[divyanshisrivastava395]

Hello @utksh1
I am contributing under GSSoC'26. I would like to work on this issue. please assign it to me.
/assign me under gssoc

[anshul23102]

Interested in contributing to this under NSoC'26. This is a valuable issue addressing important functionality/quality. Happy to take this on.

/assign

[anshul23102]

Interested in contributing under NSoC'26. This is a valuable issue. Happy to work on it.

/assign