pending property
Required pending indicator pipeline Bloom<bool>.
When true, indicates an asynchronous background operation is in flight.
When preserveDataOnPending is false and prior valid data exists (target.hasData),
renders loading during background re-evaluation. If in an error state, retains the error view.
Performance Contract (Zero-Rebuild SWR):
When preserveDataOnPending is true (default) and valid data is present, build does NOT
subscribe to pending. This ensures that background revalidation pulses do not rebuild
the main data subtree, allowing BloomPendingIndicator to track progress independently.
Implementation
final Bloom<bool> pending;