fix astro example, fix svelte SSR, fix portals

examples/astro-xyflow/src/components/SvelteFlowInitialExample/index.svelte

@@ -1,11 +1,10 @@
 <script lang="ts">
-  import { writable } from 'svelte/store';
   import { SvelteFlow, Controls, Background, BackgroundVariant, type Node, type Edge } from '@xyflow/svelte';
 
   import '@xyflow/svelte/dist/style.css';
   import CustomNode from './CustomNode.svelte';
 
-  const nodes = writable<Node[]>([
+  let nodes = $state.raw<Node[]>([
     {
       id: '1',
       position: { x: 0, y: 0 },
@@ -24,7 +23,7 @@
     },
   ]);
 
-  const edges = writable<Edge[]>([{ id: '1-2', source: '1', target: '2' }]);
+  let edges = $state.raw<Edge[]>([{ id: '1-2', source: '1', target: '2' }]);
 
   const nodeTypes = {
     'input-node': CustomNode,
@@ -32,7 +31,7 @@
 </script>
 
 <div style="height: 400px; width: 700px;">
-  <SvelteFlow {nodes} {edges} {nodeTypes} fitView width={700} height={400}>
+  <SvelteFlow bind:nodes bind:edges {nodeTypes} fitView width={700} height={400}>
     <Controls />
     <Background variant={BackgroundVariant.Dots} />
   </SvelteFlow>