Function lease_file 

pub fn lease_file(root: &Path, local_half: &str) -> PathBuf

Where the lease of the checkout at root lives, given the repository-relative path of its local half (.ai/local). The one composition of that path; every reader of a lease that is not this process’s own repository — another checkout’s, in the server’s status or the environment snapshot — goes through here.

use majordomus_cli::lease::lease_file;
use std::path::Path;
assert_eq!(
    lease_file(Path::new("/r"), ".ai/local"),
    Path::new("/r/.ai/local/state/mcp/server.json")
);