feat: add ItemOverviewDto for enriched item data in items list

feat: implement CustomerDetailPage for detailed customer view and editing

feat: create CustomersPage for listing and managing customers with filters

feat: add ColumnsMenu component for customizable table columns visibility

feat: implement CSV export functionality for data download

feat: add customer code generation logic for unique customer identifiers

Frontend/erp-system/components/Layouts/AppSidebar.tsx

@@ -116,8 +116,6 @@ const navItems: {
       { title: "Purchase Orders", code: "procurement.purchase-orders", href: "/dashboard/procurement/purchase-orders", icon: ShoppingCart },
       { title: "Purchase Returns", code: "procurement.purchase-returns", href: "/dashboard/procurement/purchase-returns", icon: PackageX },
       { title: "Vendors", code: "procurement.vendors", href: "/dashboard/vendors", icon: Truck },
-      { title: "Requisitions", code: "procurement.requisitions", href: "/dashboard/procurement/requisitions", icon: ClipboardList },
-      { title: "RFQs", code: "procurement.rfqs", href: "/dashboard/procurement/rfqs", icon: FileText },
     ],
   },
   {
@@ -129,6 +127,9 @@ const navItems: {
     chevron: true,
     children: [
       { title: "Sales", code: "sales.invoices", href: "/dashboard/sales/invoices", icon: FileText },
+      // Reuses the sales.invoices permission code — customers aren't yet their own
+      // seeded NavItem/Permission on the backend, so this rides along with Sales access.
+      { title: "Customers", code: "sales.invoices", href: "/dashboard/customers", icon: Users },
       { title: "Bundle Templates", code: "sales.bundle-templates", href: "/dashboard/sales/bundles/templates", icon: LayoutList },
       { title: "Free Issues", code: "sales.free-issues", href: "/dashboard/sales/free-issues", icon: PackageX },
       { title: "Day End", code: "sales.day-end", href: "/dashboard/sales/day-end", icon: Lock },