Handle branch checkout and dedupe for slash-named remotes

- add `remoteName` to git branch contract metadata
- resolve remote refs using full remote names (including slashes)
- avoid fallback to wrong local checkout when remote ref is missing
- update branch toolbar logic/tests to map and dedupe remote branches correctly
ff3e81de21Julius Marminge committed on 3/1/2026, 4:32:39 AMparente7a3e93
6 files changedLine totals unavailable