Moving watermarks after each accepted send kept the install ID and the notice baseline out of step: pre-consent notices went out, notices raised before the first send were dropped, and a send that finished after an off/on toggle overwrote the new identity's baseline. health.notices now carries cumulative counts since the install ID was created. Creating an ID copies the lifetime counts into the existing reported_* columns before the state file names it, and nothing is written after a send, so the backend diffs consecutive reports per install ID.