Remove the 'selected store' notification from the dashboard

Remove the badge component that displayed "Magasin sélectionné" when a store was selected by an admin user on the Dashboard page.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: e437ffed-c31b-44eb-9fd5-b6f9faa8e7ce
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/e437ffed-c31b-44eb-9fd5-b6f9faa8e7ce/aVFsaJG

client/src/pages/Dashboard.tsx

@@ -234,11 +234,6 @@ export default function Dashboard() {
               Vue d'ensemble des performances et statistiques
             </p>
           </div>
-          {selectedStoreId && user?.role === 'admin' && (
-            <Badge variant="outline" className="text-blue-700 border-blue-300 w-fit">
-              Magasin sélectionné
-            </Badge>
-          )}
         </div>
       </div>