Move error handling for filesystem to frontend

svelte/src/filesystem/ErrorPage.svelte

@@ -0,0 +1,48 @@
+<script lang="ts">
+    import TextBlock from "layout/TextBlock.svelte";
+import { type FSNavigator } from "./FSNavigator";
+import { onMount } from "svelte";
+import { breadcrumbs_store } from "wrap/BreadcrumbStore";
+
+let {
+	nav
+}: {
+	nav: FSNavigator;
+} = $props();
+
+onMount(() => {
+	return nav.subscribe(nav => {
+		breadcrumbs_store.set(breadcrumbs)
+	})
+
+
+})
+</script>
+
+{#snippet breadcrumbs()}
+	{$nav.navigation_error}
+{/snippet}
+
+<TextBlock>
+	{#if $nav.navigation_error === "not_found" || $nav.navigation_error === "path_not_found"}
+		<h1>Page not found</h1>
+		<p>
+			This page could not be found.
+		</p>
+	{:else if $nav.navigation_error === "permission_denied" || $nav.navigation_error === "forbidden"}
+		<h1>Permission denied</h1>
+		<p>
+			You are not allowed to access this resource.
+		</p>
+	{:else if $nav.navigation_error === "unavailable_for_legal_reasons"}
+		<h1>Unavailable for legal reasons</h1>
+		<p>
+			This content has been removed for breaking the law.
+		</p>
+	{:else}
+		<h1>Unknown error code</h1>
+		<p>
+			{$nav.navigation_error}
+		</p>
+	{/if}
+</TextBlock>