Function with_state 

pub fn with_state<F>(
    repo_root: &Path,
    home_override: Option<&Path>,
    f: F,
) -> Result<StateV2, WorktreeError>
where
    F: FnOnce(&mut StateV2) -> Result<(), WorktreeError>,

Read-modify-write helper: acquires state.lock, reads state, applies the closure, then writes back. The lock is released as soon as this function returns — callers must not perform long-running work inside the closure.

Uses DEFAULT_LOCK_TIMEOUT_MS. Prefer with_state_timeout from inside a Manager so Config.lock_timeout_ms is honored.