fix: mostrar Google Ads desde ad_daily cuando kpi_weekly está vacío

kpi_weekly es una MV de solo lectura sin canales paid; canal/seguimiento
ahora hacen fallback a ad_daily. Bump Google Ads API a v21 en sync.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/app/dashboard/kpis/page.tsx

@@ -8,9 +8,9 @@ import {
   KpiWeeklyRow,
   buildChannelSeries,
   buildComparisons,
+  resolveWeeklyRows,
   sumDaily,
   sumWeekly,
-  weeklyFromDaily,
 } from '@/lib/metrics';
 import { isAgencyRole, userRole } from '@/lib/agency';
 
@@ -65,13 +65,7 @@ export default async function KpisPage() {
     daily = (d as AdDailyRow[]) || [];
   }
 
-  // kpi_weekly is often a stale MV — prefer ad_daily when it has more signal
-  const fromDaily = weeklyFromDaily(daily);
-  const weeklySpend = weekly.reduce((a, r) => a + Number(r.total_spend || 0), 0);
-  const dailySpend = daily.reduce((a, r) => a + Number(r.spend || 0), 0);
-  if (fromDaily.length && dailySpend >= weeklySpend) {
-    weekly = fromDaily;
-  }
+  weekly = resolveWeeklyRows(weekly, daily);
 
   const comparisons = buildComparisons(weekly);
   const month =