fix release fetch and GitHub release URL routing

[justjxke]

Summary

This PR fixes release pages showing “No releases yet” for repos that do have releases, and improves GitHub release URL handling in Better Hub.

Problem

• Some repos could end up displaying an empty releases state due to stale cached empty release data.
• GitHub release URLs (especially tag/latest variants) were not consistently mapped to Better Hub internal release routes.

Changes

• Added a cache-heal path for repo releases:
  • If cached release data is empty for an authenticated repo, perform one authenticated refetch and refresh cache.
• Improved GitHub URL parsing/mapping for releases:
  • Support /releases
  • Support /releases/tag/:tag
  • Handle latest release route via canonical internal path.
• Added route handlers:
  • .../releases/tag/[tag]/page.tsx to normalize GitHub-style release tag URLs.
  • .../releases/_latest/page.tsx to resolve latest release and redirect to canonical tag release page.
• Kept release fetching on the authenticated Octokit path (no public unauthenticated fallback path).

Verification

• Typecheck passed:
  • bun --cwd apps/web typecheck
• Manual validation:
  • Repo releases that previously rendered empty now render correctly.
  • GitHub release links resolve to the expected Better Hub routes.

Notes

I considered messing with the redirect URL buttons since they seemed redundant but I wasn't sure what to make them redirect to, so if you have the browser extension they redirect you to 404.

[vercel]

@justjxke is attempting to deploy a commit to the better-auth Team on Vercel.

A member of the Team first needs to authorize it.

[justjxke]

The commit above is a bit of a bandaid fix.