0487 — The alert domain owns measurement and decision; producer and consumer inject it

Context. Both the producer and consumer sides need the check conditions (for the register-time pass and the executors). The first build followed the “write it on each side’s datastore” convention and copied the queries, thresholds, and texts into each side — two drifting copies of one domain’s logic.

Decision. The condition lives once, as the Evaluate controller in each check’s package (pkg/alert/partitioncount, pkg/alert/compactionreadcost), and producer/consumer inject it as evaluators []alert.Evaluator. The per-side copies were deleted.

Consequences. One home per condition — a threshold or query change happens once. Clarified rule: the duplication convention covers shared needs each side implements in its own style, not another domain’s measurement-and-decision logic. Rejected: per-side copies of the check queries and thresholds — that convention was misapplied here.