fix: support cloning non-default branches by parsing branch from URL

[chrisijoyah]

This PR fixes the issue with importing repositories from branches that are not the default.

Changes

• Extracts the branch name from the URL fragment and passes it to the isomorphic-git clone operation.
• Ensures the base repository URL is used for authentication and clone operations.
• Improves reliability when importing repositories from non-default branches.

These updates make it possible to clone and work with any branch, not just the default, and improve authentication handling.

[timmillwood]

Looks good.
Nice simply but impactful fix.