Static HC_FUSED_PRE_DISPATCHES 

pub static HC_FUSED_PRE_DISPATCHES: AtomicU64

Engagement counter for the fused pre-chain door’s =1 arm: incremented at the arm’s own call site, announced once per boot — the spec-engagement receipt the gate and any box A/B arm must show ([bf16-mmv] RESIDENT lesson: engagement lines are receipts, never inferred).