Remove the role management menu from the sidebar

Remove the "Gestion des Rôles" menu item and its associated icon and role restriction from the Sidebar component.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: b163d4c0-de5e-4f4e-a9c0-aed4c7049718
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/b163d4c0-de5e-4f4e-a9c0-aed4c7049718/ByygiiM

client/src/components/Sidebar.tsx

@@ -13,7 +13,6 @@ import {
   LogOut,
   FileText,
   Megaphone,
-  Shield,
   Database,
   ShoppingCart,
   Clock,
@@ -134,12 +133,6 @@ export default function Sidebar() {
       icon: UserCog, 
       roles: ["admin"] 
     },
-    { 
-      path: "/roles", 
-      label: "Gestion des Rôles", 
-      icon: Shield, 
-      roles: ["admin"] 
-    },
     { 
       path: "/nocodb-config", 
       label: "Configuration NocoDB",