pub fn add(
project_root: &Path,
path: &Path,
branch: &str,
start_point: &str,
create_branch: bool,
) -> Result<(), WorktreeError>Expand description
Add a worktree.
When create_branch is set, runs git worktree add -b <branch> <path> <start_point> (creating branch off start_point). Otherwise runs
git worktree add <path> <branch> to check out an existing branch.
Returns WorktreeError::Exists if path already exists — callers decide
whether to remove-and-readd (refresh) or surface the error.