fix: add appearance panel route page (#585)

dashboard/app/panel/appearance/page.tsx

@@ -0,0 +1,17 @@
+export const dynamic = 'error'
+
+import { redirect } from 'next/navigation'
+
+import { resolveExtensionRouteComponent } from '@extensions/loader'
+
+export default async function AppearancePage() {
+  try {
+    const Component = await resolveExtensionRouteComponent('/panel/appearance')
+    return <Component />
+  } catch (error) {
+    if (error instanceof Error && error.message.includes('disabled')) {
+      redirect('/panel')
+    }
+    throw error
+  }
+}