bug: GitHub repo list never marks already-registered repos as registered

[sauravpanda]

Summary

The GitHub repo browser compares repo names against local filesystem paths, so the "Registered" state is effectively wrong.

Evidence

• src/components/RepoList.tsx lines 26-29 build registeredPaths from projects.map((p) => p.local_path).
• The rendered GitHub repo rows check registeredPaths.has(repo.name) at lines 209-217.
• A repo name like workroot will almost never equal an absolute local path like /Users/.../workroot.

Impact

Already-registered repos still show a Clone CTA, which can lead to duplicate clone attempts and confusing UX.

Suggested fix

• Compare on a stable shared key such as github_url, repo full name, or the final path segment derived from local_path.
• Add a small unit test around the registration-state predicate so this does not regress.