The one-way address where every family's impact units are retired forever — in, never out.
The registry sink is a code-bearing address with no exit door. When a burn-boost family disposes of its impact units, they are retired into this registry, and there is no function that can bring them back out.
Retired means retired: the units go in and are held forever, never destroyed and never re-sold. The registry is the permanent, public showcase of the impact the network has locked away.
You can watch the registry's balances only grow — that is the design. Every burn-boost family except Art retires here (Art burns through its own official burn instead).