improvement: multi organization possibility implemented for users (owners and staffs)

frontend/src/components/ui/Sidebar.tsx

@@ -10,7 +10,8 @@ import {
   UserCog,
   FlaskConical,
   FileText,
-  CreditCard
+  CreditCard,
+  Building2
 } from 'lucide-react';
 
 const menu = [
@@ -21,6 +22,7 @@ const menu = [
   { name: 'Lab Management', path: '/lab', icon: FlaskConical },
   { name: 'Billing', path: '/billing', icon: CreditCard },
   { name: 'Reports', path: '/reports', icon: FileText },
+  { name: 'Organizations', path: '/select-organization', icon: Building2 },
 ];
 
 function Sidebar() {