Constant FN_ID_NUB_INVOKE_WORKER 

pub const FN_ID_NUB_INVOKE_WORKER: u32 = 7;

fn_id for a long-lived per-vCPU invoke worker. Payload is a little-endian u32 lane index. The function does not use the legacy rkyv response ring; it polls that lane’s ParallelInvokeSlot in scratch memory, runs invokes with run_top_on_lane, and writes results back into the same slot.