Release v19.37.6

Kernel startup no longer re-writes unchanged reactor registration metadata for every tenant, and startup retries under storage saturation are bounded and cancellable. This addresses Chronicle replicas crash-looping at startup with MongoDB connection wait-queue exhaustion and 30-second registration timeouts when many tenants register at once.

Fixed

• Reactor registration compares persisted metadata against the runtime's unrestricted sentinels, so unchanged definitions are no longer rewritten on every restart or reconnect.
• Startup retries under storage saturation are bounded, honor shutdown, and never continue past a required step that failed.
• SQL storage no longer writes an event type's display string into its id column for reactor definitions; malformed rows are rewritten on the next registration.
• A read model's definition is not rewritten when unchanged, and a failed write no longer leaves in-memory state ahead of storage.