fix(scheduler): убрать двойной SaveCheckRun (Checker персистит), SetDrift через CountDriftDomains, resolved после error

internal/store/queries/domains.sql

@@ -34,3 +34,6 @@ SELECT last_check_status FROM domains WHERE id = $1;
 
 -- name: SetDomainStatus :exec
 UPDATE domains SET last_check_status = $2 WHERE id = $1;
+
+-- name: CountDriftDomains :one
+SELECT count(*) FROM domains WHERE last_check_status = 'drift';