Sandbox only. This endpoint exists on api-sandbox.clc.solutions and not on
live: it makes CLC emit an event that never happened, which is exactly what you
want while building a handler and never what you want against real borrowers.

Requires scope webhook:write.

Sends a real, signed HTTP request to that webhook's URL carrying the payload you
supply, then reports what your endpoint answered. Nothing is written to the event
log and no lending state changes.

Deliberately takes no Idempotency-Key: repeating a simulation on purpose is the
whole point of it.