Function try_acquire_all 

pub async fn try_acquire_all(
    map: &AgentLockMap,
    coords: &[(PathBuf, String)],
) -> Option<Vec<AgentLock>>

Acquire EVERY coord NON-BLOCKING, all-or-nothing, concurrently. None if any coord is busy (in-process guard taken OR cross-process held) — the ones that were acquired drop here, releasing them. Deadlock-free: every leg is a non-blocking try, so acquisition order never matters.