Function is_hex_40

crates/opencode-session/src/snapshot.rs:284–286

(s: &str)

    use tempfile::tempdir;

    fn is_hex_40(s: &str) -> bool {
        s.len() == 40 && s.chars().all(|c| c.is_ascii_hexdigit())
    }

    #[test]
    fn track_diff_restore_handles_uncommitted_worktree() {