Svelte: toArray sub-queries returning null values when inspected

• [ x] I've validated the bug against the latest version of DB packages

Describe the bug
When using svelte-db, queries that involve a toArray sub query become unstable and produce null values (mainly on item insert, but has also caused issues with the entire dataset) while the query is inspected with the $inspect rune.

To Reproduce
In this basic reproduction, the code will throw an error as follows: TypeError: can't access property "length", $.get(...).comments is null. This is mainly when the new item button is pressed and an item is inserted, but also on the first page load. If you remove the $inspect on the query, the behaviour returns to the standard and the toArray is initialized correctly with each item.

<script lang="ts">
	import { useLiveQuery, toArray, eq } from "@tanstack/svelte-db";
	import { query_client } from "$lib/query.svelte";
	import { GetComments } from "$lib/remote/comments.remote";
	import { CreateTask, GetTasks } from "$lib/remote/tasks.remote";
	import { createCollection } from "@tanstack/db";
	import { queryCollectionOptions } from "@tanstack/query-db-collection";

	const TaskCollection = createCollection(
		queryCollectionOptions({
			queryKey: ["tasks"],
			queryFn: async () => {
				const tasks = await GetTasks().run();

				return tasks;
			},
			getKey: (task) => task.id,
			queryClient: query_client,
			onInsert: async ({ transaction }) => {
				await Promise.all(
					transaction.mutations.map((mut) => {
						return CreateTask(mut.modified);
					}),
				);

				query_client.invalidateQueries({ queryKey: ["tasks"] });
			},
		}),
	);

	const CommentsCollection = createCollection(
		queryCollectionOptions({
			queryKey: ["comments"],
			queryFn: async () => {
				const comments = await GetComments().run();

				return comments;
			},
			queryClient: query_client,
			getKey: (comment) => comment.id,
		}),
	);

	const query = useLiveQuery((q) =>
		q.from({ task: TaskCollection }).select(({ task }) => ({
			id: task.id,
			title: task.title,
			comments: toArray(
				q
					.from({ comment: CommentsCollection })
					.where(({ comment }) => eq(task.id, comment.task_id)),
			),
		})),
	);

	$inspect(query);
</script>

{#each query.data as task (task.id)}
	<p>{task.title} ({task.comments.length} Comments)</p>
{/each}

<button
	onclick={() =>
		TaskCollection.insert({
			id: crypto.randomUUID(),
			title: `Task ${crypto.randomUUID()}`,
			priority: 1,
		})}>New Task</button
>

Expected behavior
The expected behaviour is that adding an inspect to view the output of a query should not affect the reactivity of the contents, and that the data output aligns with the expected type. In this case, toArray does not display as a nullable type.

Screenshots

Desktop (please complete the following information):

• OS: MacOS
• Browser: Chrome & Zen
• Version: (Chrome: 147.0.7727.102, Zen: 1.19.4b)

Additional context
N/A

Start with the provided Svelte reproduction, focusing on the useLiveQuery query that combines toArray with the $inspect rune and the insert handler. Verify the behavior on initial load and after inserting a task; done means inspected queries retain initialized comment arrays and no longer produce null values or the reported length error.