feat: add warning if passkeys missing

frontend/src/lib/components/ui/alert/alert.svelte

@@ -0,0 +1,17 @@
+<script lang="ts">
+	import type { HTMLAttributes } from "svelte/elements";
+	import { type Variant, alertVariants } from "./index.js";
+	import { cn } from "$lib/utils/style.js";
+
+	type $$Props = HTMLAttributes<HTMLDivElement> & {
+		variant?: Variant;
+	};
+
+	let className: $$Props["class"] = undefined;
+	export let variant: $$Props["variant"] = "default";
+	export { className as class };
+</script>
+
+<div class={cn(alertVariants({ variant }), className)} {...$$restProps} role="alert">
+	<slot />
+</div>