Release v16.26.2

Fixed

• Kernel event types are re-registered for the System event store after ResetKernelState(), so the kernel's own events — such as ApplicationAuthenticated on every authentication — keep appending instead of failing with MissingEventSchemaForEventType for the rest of the kernel's lifetime (#3687)
• ReadModelScenario<T> isolates each read model instance's state by event source, so [ChildrenFrom] children no longer accumulate onto a document seeded later in the same scenario (#3688)