Git config check for on-demand fetching can now target a named remote

In a partial git clone, some data is fetched only when it is needed (a "lazy fetch"). Claude Code checks the repository's git configuration before allowing this. That check can now be pointed at a specific named remote, a remote being a server git fetches from.

When it is:

• It looks at that remote and at any remotes.<name> group setting.
• It fails with named_remote_without_url unless the repository's own config sets remote.<name>.url.
• It sets GIT_NO_LAZY_FETCH=1 and reports "GIT_NO_LAZY_FETCH is set, which switches this command off too".

Before, the check only ever looked at the remote that supplies missing data in a partial clone.