Install git_hoox shims.
mix git_hoox.install # refuse if user hook exists
mix git_hoox.install --force # backup + overwrite shims (and config)
mix git_hoox.install --dry-run # plan only, write nothing
mix git_hoox.install --scaffold # also write a starter .git_hoox.exsDetects core.hooksPath and worktrees via git rev-parse --git-path hooks.