[WIP] Add native enum support for user roles

[Copilot]

Thanks for the feedback on #110. I've created this new PR, which merges into #110, to address your comment. I will work on the changes and keep this PR's description up to date as I make progress.

Original PR: #110
Triggering comment (#110 (comment)):

@copilot review.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[coderabbitai]

Important

Review skipped

Bot user detected.

To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}