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/api/ai/auto-labels/route.ts

@@ -4,6 +4,7 @@ import { auth } from '@/auth'
 import { autoLabelCreationService } from '@/lib/ai/services'
 import { getAISettings } from '@/app/actions/ai-settings'
 import { hasUserAiConsent } from '@/lib/consent/server-consent'
+import { withAiQuota, handleQuotaHttpError } from '@/lib/ai-quota'
 
 /**
  * POST /api/ai/auto-labels - Suggest new labels for a notebook
@@ -59,11 +60,16 @@ export async function POST(request: NextRequest) {
       )
     }
 
-    // Get label suggestions
-    const suggestions = await autoLabelCreationService.suggestLabels(
-      notebookId,
+    const suggestions = await withAiQuota(
       session.user.id,
-      language
+      'auto_tag',
+      () =>
+        autoLabelCreationService.suggestLabels(
+          notebookId,
+          session.user!.id,
+          language,
+        ),
+      { lane: 'tags' },
     )
 
     if (!suggestions) {
@@ -79,8 +85,10 @@ export async function POST(request: NextRequest) {
       data: suggestions,
     })
   } catch (error) {
+    const quotaResp = handleQuotaHttpError(error)
+    if (quotaResp) return quotaResp
     console.error('[/api/ai/auto-labels] POST failed:', error)
-    return NextResponse.json({ success: true, data: null })
+    return NextResponse.json({ success: false, error: 'auto_labels_failed' }, { status: 500 })
   }
 }