feat: api key authentication (#291)

Co-authored-by: Elias Schneider <login@eliasschneider.com>

frontend/src/lib/components/ui/calendar/calendar-header.svelte

@@ -0,0 +1,16 @@
+<script lang="ts">
+	import { Calendar as CalendarPrimitive } from "bits-ui";
+	import { cn } from "$lib/utils/style.js";
+
+	type $$Props = CalendarPrimitive.HeaderProps;
+
+	let className: $$Props["class"] = undefined;
+	export { className as class };
+</script>
+
+<CalendarPrimitive.Header
+	class={cn("relative flex w-full items-center justify-between pt-1", className)}
+	{...$$restProps}
+>
+	<slot />
+</CalendarPrimitive.Header>