pyproject(fix[uv.lock]) Update libvcs lock to include refs/heads disambiguation

why: uv.lock pinned libvcs to commit e082804 (before the refs/heads/
fix at b9b14a4), so uv run silently overwrote any manual editable
install with the old version on every invocation.
what:
- Run uv lock --upgrade-package libvcs to pick up remote HEAD (34a9ea5)

Author: tony