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/lib/dashboard/paths.service.ts

@@ -1,6 +1,7 @@
 import 'server-only'
 
 import prisma from '@/lib/prisma'
+import { clusteringService } from '@/lib/ai/services/clustering.service'
 import type { DashboardPath } from '@/lib/dashboard/path-types'
 
 export type { DashboardPath, DashboardPathType } from '@/lib/dashboard/path-types'
@@ -248,7 +249,7 @@ export async function buildDashboardPaths(input: BuildPathsInput): Promise<Dashb
         id: `explore-cluster-${focusClusterId}`,
         type: 'explore',
         priority: 60,
-        title: cluster.name || `Cluster ${focusClusterId}`,
+        title: clusteringService.displayName(cluster.name, focusClusterId),
         description: `${cluster.noteCount} notes in this theme`,
         actionKey: 'exploreTheme',
         clusterAId: focusClusterId,