fix(quotas): unifier le décompte IA (BYOK, rollback) et combler les fuites

Centralise la réserve via ai-quota, corrige admin unavailable (-1), brancher les routes sans quota et le host-pays brainstorm, avec usage-meter élargi, noms de clusters, MCP et ajustements dashboard/insights.

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

memento-note/app/actions/admin-billing.ts

@@ -7,6 +7,7 @@ import { VALID_FEATURES, getCurrentPeriodKey } from '@/lib/quota-utils'
 import {
   getAllEntitlementsForAdmin,
   invalidateEntitlementCache,
+  ENTITLEMENT_UNAVAILABLE,
   type SubscriptionTier as TierType,
 } from '@/lib/plan-entitlements'
 import { logAuditEventAsync } from '@/lib/audit-log'
@@ -73,9 +74,20 @@ export async function updatePlanEntitlement(
   }
 
   if (mode === 'unavailable') {
-    await prisma.planEntitlement.deleteMany({
-      where: { tier: tier as SubscriptionTier, feature },
-    })
+    await prisma.planEntitlement.upsert({
+      where: {
+        tier_feature: {
+          tier: tier as SubscriptionTier,
+          feature,
+        },
+      },
+      update: { limitValue: ENTITLEMENT_UNAVAILABLE },
+      create: {
+        tier: tier as SubscriptionTier,
+        feature,
+        limitValue: ENTITLEMENT_UNAVAILABLE,
+      },
+    });
   } else {
     await prisma.planEntitlement.upsert({
       where: {
@@ -158,7 +170,7 @@ export async function updateBillingConfig(data: Record<string, string>) {
 
 async function getUsageOverviewInternal() {
   const period = getCurrentPeriodKey()
-  const periodStart = new Date(`${period}-01`)
+  const periodStart = new Date(`${period}-01T00:00:00.000Z`)
 
   const aggregated = await prisma.usageLog.groupBy({
     by: ['feature'],