Briefly back to CHECKING after reaching ACTIVE status

Under very specific conditions after startup, nodes can flip to ACTIVE even when < 2/3rd stake is not online.

We base the transition to active on the occurrence of a self event reaching consensus.
Even if not all nodes are up and active, pre-shutdown events replayed from PCES can be enough to reach consensus on the freeze round +1 producing an early transition to active, only to later freeze up to when we reached the necessary quorum, flipping it back to checking during that period.

We should require the self event that reached consensus to have been created in this run before moving the node to ACTIVE

Start by tracing the startup transition to ACTIVE and how consensus on a self event is determined, then inspect the handling of events replayed from PCES. Reproduce the case with pre-shutdown events and incomplete stake availability; it is done when a self event from a prior run cannot trigger ACTIVE, while one created in the current run can.

Written by the indexing model from the issue text.