add theme change + high res icon

app/src/routes/+page.svelte

@@ -2,6 +2,7 @@
     import {title, family_tree} from '$lib/paraglide/messages.js';
     import { SvelteFlowProvider,Background, BackgroundVariant, SvelteFlow, Controls, MiniMap } from '@xyflow/svelte';
     import type { Node, Edge, NodeTypes, NodeProps } from '@xyflow/svelte';
+	import ThemeButton from '$lib/theme-select.svelte';
 
     let nodes = $state.raw<Node[]>([]);
     let edges = $state.raw<Edge[]>([]);
@@ -11,6 +12,10 @@
 	<title>{title({ page: family_tree() })}</title>
 </svelte:head>
 
+<div class="absolute top-2 right-2">
+    <ThemeButton />
+</div>
+
 <div style="height:100vh;">
 	<SvelteFlowProvider>
 		<SvelteFlow bind:nodes bind:edges class="bg-base-100" fitView onlyRenderVisibleElements>