Remove item management feature from frontend and backend, and add a pending skeleton component.

frontend/src/components/Sidebar/AppSidebar.tsx

@@ -1,4 +1,4 @@
-import { Briefcase, Home, MapPin, Users } from "lucide-react"
+import { Home, MapPin, Users } from "lucide-react"
 
 import { SidebarAppearance } from "@/components/Common/Appearance"
 import { Logo } from "@/components/Common/Logo"
@@ -15,7 +15,6 @@ import { User } from "./User"
 const baseItems: Item[] = [
   { icon: Home, title: "Dashboard", path: "/" },
   { icon: MapPin, title: "Locations", path: "/locations" },
-  { icon: Briefcase, title: "Items", path: "/items" },
 ]
 
 export function AppSidebar() {