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

internal/store/db/domains.sql.go

@@ -12,6 +12,17 @@ import (
 	dto "github.com/vasyakrg/dns-autoresolver/internal/store/dto"
 )
 
+const countDriftDomains = `-- name: CountDriftDomains :one
+SELECT count(*) FROM domains WHERE last_check_status = 'drift'
+`
+
+func (q *Queries) CountDriftDomains(ctx context.Context) (int64, error) {
+	row := q.db.QueryRow(ctx, countDriftDomains)
+	var count int64
+	err := row.Scan(&count)
+	return count, err
+}
+
 const createDomain = `-- name: CreateDomain :one
 INSERT INTO domains (id, project_id, provider_account_id, zone_name, zone_id, template_id)
 VALUES ($1, $2, $3, $4, $5, $6)

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';

internal/store/tenant.go

@@ -258,6 +258,14 @@ func (s *Store) SetDomainStatus(ctx context.Context, domainID uuid.UUID, status
 	return s.q.SetDomainStatus(ctx, db.SetDomainStatusParams{ID: domainID, LastCheckStatus: status})
 }
 
+// CountDriftDomains returns the current number of domains system-wide whose
+// last check status is "drift". This is a global count (not per-project) —
+// it backs the dns_ar_drift_domains gauge, which is a system-level metric.
+func (s *Store) CountDriftDomains(ctx context.Context) (int, error) {
+	n, err := s.q.CountDriftDomains(ctx)
+	return int(n), err
+}
+
 // User and Project are provider-neutral domain structs for the auth/tenant
 // layer (Фаза 2), mirroring the Account/Template/Domain wrappers above so
 // callers never need to import internal/store/db directly.