feat: add theme toggle to admin sidebars and update form list to use full-row navigation links

components/admin-shell.tsx

@@ -17,6 +17,7 @@ import {
   SidebarTrigger,
 } from "@/components/ui/sidebar";
 import { ClipboardList, Server, LayoutDashboard } from "lucide-react";
+import { ThemeToggle } from "@/components/theme-toggle";
 
 export function AdminShell({ children }: { children: React.ReactNode }) {
   const pathname = usePathname();
@@ -25,10 +26,11 @@ export function AdminShell({ children }: { children: React.ReactNode }) {
     <SidebarProvider>
       <div className="flex w-full min-h-screen bg-background text-foreground">
         <Sidebar variant="sidebar" collapsible="icon">
-          <SidebarHeader className="border-b border-border py-4 px-4">
+          <SidebarHeader className="border-b border-border py-4 px-4 flex flex-row items-center justify-between">
             <span className="font-bold tracking-wider text-primary text-sm uppercase">
               Admin
             </span>
+            <ThemeToggle />
           </SidebarHeader>
 
           <SidebarContent>