Svelte boundaries fail with remote function and being called in script

[Hysterelius]

Describe the bug

When a remote function is called and the result is awaited in <svelte:boundary> while there is also a remote function which is called without a boundary.

i.e., like so

<script lang="ts">
	import { getDelayedData } from './data.remote';

	const moreData = await getDelayedData();
</script>

<h1>Dashboard</h1>

<svelte:boundary>
	<span>Protected Data</span>
	<p>Secret: {await getDelayedData()}</p>
	{#snippet pending()}
		<p>loading...</p>
	{/snippet}
</svelte:boundary>

<pre>
    {moreData}
</pre>

The page will forever show the loading state.

However, if you call the function inline like so, it works correctly,

<script lang="ts">
	import { getDelayedData } from './data.remote';
</script>

<h1>Dashboard</h1>

<svelte:boundary>
	<span>Protected Data</span>
	<p>Secret: {await getDelayedData()}</p>
	{#snippet pending()}
		<p>loading...</p>
	{/snippet}
</svelte:boundary>

<pre>
    {await getDelayedData()}
</pre>

Reproduction

Full repo is here, https://github.com/Hysterelius/better-auth-sveltekit-demo

Logs

System Info

Binaries:
    Node: 24.3.0 - /home/hys/.local/share/pnpm/node
    npm: 11.4.2 - /home/hys/.local/share/pnpm/npm
    pnpm: 10.18.3 - /home/hys/.local/share/pnpm/pnpm
    Deno: 2.3.6 - /home/hys/.deno/bin/deno
  Browsers:
    Chrome: 141.0.7390.107
    Firefox: 144.0
    Firefox Developer Edition: 144.0
  npmPackages:
    svelte: ^5.41.0 => 5.41.0

Severity

annoyance

[qwacko]

You should have the await function inside a derived rune otherwise it won't be reactive. So const moreData = await getDelayedData(); should be const moreData = $derived(await getDelayedData());.

[dummdidumm]

Reducing this and running this playground locally with SSR there's a hydration mismatch. Might be the underlying reason.