UI Stabilization: Global color theme updates (#75B2D6), AI Assistant styling refactor, and navigation fixes

memento-note/lib/ai/services/auto-label-creation.service.ts

@@ -437,10 +437,11 @@ Deine Antwort (nur JSON):
 
       const label = await tx.label.upsert({
         where: { notebookId_name: { notebookId, name: suggestedLabel.name } as any },
-        update: {},
+        update: { type: 'ai' },  // Update type to AI if it exists as user label
         create: {
           name: suggestedLabel.name,
           color: 'gray',
+          type: 'ai',  // Mark as AI-generated
           notebookId,
           userId,
         },