Function bring_up 

pub async fn bring_up<CS: CounterStore + 'static>(
    mac_cell: &'static DeviceNodeMacCell<CS>,
    identity_secret: &[u8; 32],
    node_seed: [u8; 32],
    t_frame_ms: u32,
    counters: CS,
    duty: &'static DutyLedger,
    hooks: NodeHooks,
) -> DeviceNodeParts<CS>

Construct the MAC around the device identity and wire up the node. Call at most once. The identity is never absent — boot generates and persists one when the journal is empty — so there is no “unprovisioned” path here.

t_frame_ms is the worst-case airtime hint for the MAC scheduler. The caller spawns the loops and must do so promptly: NODE_UP is set here, so a PROP_IDENT read arriving between this returning and the spawns would wait on the signal.