Function acquire_or_emit 

pub fn acquire_or_emit(
    socket_dir: &Path,
    command: Command,
    json: bool,
    silent: bool,
    dry_run: bool,
    timeout: Duration,
    break_lock: bool,
) -> Result<LockAcquired, i32>

Try to acquire <socket_dir>/apply.lock and return the guard, or emit a failure envelope and a non-zero exit code.

command selects the envelope’s command field so downstream consumers see apply / rollback / repair / remove rather than a generic “lock failed”. dry_run is plumbed through to the envelope’s dry_run field for the (rare) case where lock contention happens during a dry-run apply.

timeout = Duration::ZERO keeps the historical non-blocking try-once shape. Positive values wait with a 100 ms backoff — see socket_patch_core::patch::apply_lock::acquire.

break_lock = true deletes <socket_dir>/apply.lock before the acquire attempt. The motivating case is a crashed prior run that left the file but no OS lock. When the file exists and is successfully removed the return value’s broke_lock is true and the caller should attach a lock_broken warning event to their envelope.