feat: add account menu to the sidebar footer

frontend/src/lib/components/ui/avatar/avatar-group-count.svelte

@@ -0,0 +1,23 @@
+<script lang="ts">
+	import { cn, type WithElementRef } from "$lib/utils.js";
+	import type { HTMLAttributes } from "svelte/elements";
+
+	let {
+		ref = $bindable(null),
+		class: className,
+		children,
+		...restProps
+	}: WithElementRef<HTMLAttributes<HTMLDivElement>> = $props();
+</script>
+
+<div
+	bind:this={ref}
+	data-slot="avatar-group-count"
+	class={cn(
+		"size-8 rounded-full bg-muted text-sm text-muted-foreground group-has-data-[size=lg]/avatar-group:size-10 group-has-data-[size=sm]/avatar-group:size-6 [&>svg]:size-4 group-has-data-[size=lg]/avatar-group:[&>svg]:size-5 group-has-data-[size=sm]/avatar-group:[&>svg]:size-3 relative flex shrink-0 items-center justify-center ring-2 ring-background",
+		className
+	)}
+	{...restProps}
+>
+	{@render children?.()}
+</div>