feat(search): show spinner in search input while navigation is in-flight

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/routes/+page.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
 import { goto } from '$app/navigation';
+import { navigating } from '$app/state';
 import { untrack } from 'svelte';
 import { SvelteURLSearchParams } from 'svelte/reactivity';
 import SearchFilterBar from './SearchFilterBar.svelte';
@@ -102,6 +103,7 @@ const showRightColumn = $derived(data.canWrite || (data.incompleteDocs?.length ?
 		bind:tagQ={tagQ}
 		initialSenderName={data.initialValues?.senderName}
 		initialReceiverName={data.initialValues?.receiverName}
+		isLoading={navigating.to !== null}
 		onSearch={handleTextSearch}
 		onfocus={() => (qFocused = true)}
 		onblur={() => (qFocused = false)}

frontend/src/routes/SearchFilterBar.svelte

@@ -18,6 +18,7 @@ let {
 	showAdvanced = $bindable(false),
 	initialSenderName = '',
 	initialReceiverName = '',
+	isLoading = false,
 	onSearch,
 	onfocus,
 	onblur
@@ -34,6 +35,7 @@ let {
 	showAdvanced?: boolean;
 	initialSenderName?: string;
 	initialReceiverName?: string;
+	isLoading?: boolean;
 	onSearch: () => void;
 	onfocus?: () => void;
 	onblur?: () => void;
@@ -70,12 +72,31 @@ $effect(() => {
 				class="block w-full border-line py-2.5 pr-10 pl-3 placeholder-ink-3 shadow-sm focus:outline-none focus-visible:ring-2 focus-visible:ring-focus-ring"
 			/>
 			<div class="pointer-events-none absolute inset-y-0 right-0 flex items-center pr-3">
-				<img
-					src="/degruyter-icons/Simple/Medium-24px/SVG/Action/Mag-Glass-MD.svg"
-					alt=""
-					aria-hidden="true"
-					class="h-4 w-4 opacity-40"
-				/>
+				{#if isLoading}
+					<svg
+						role="status"
+						aria-label="Suche läuft…"
+						class="h-4 w-4 animate-spin text-ink-3"
+						xmlns="http://www.w3.org/2000/svg"
+						fill="none"
+						viewBox="0 0 24 24"
+					>
+						<circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"
+						></circle>
+						<path
+							class="opacity-75"
+							fill="currentColor"
+							d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"
+						></path>
+					</svg>
+				{:else}
+					<img
+						src="/degruyter-icons/Simple/Medium-24px/SVG/Action/Mag-Glass-MD.svg"
+						alt=""
+						aria-hidden="true"
+						class="h-4 w-4 opacity-40"
+					/>
+				{/if}
 			</div>
 		</div>
 

frontend/src/routes/SearchFilterBar.svelte.spec.ts

@@ -27,6 +27,20 @@ describe('SearchFilterBar – sort controls', () => {
 	});
 });
 
+describe('SearchFilterBar – loading spinner', () => {
+	it('shows search icon when isLoading is false', async () => {
+		render(SearchFilterBar, { ...defaultProps, sort: 'DATE', dir: 'desc', isLoading: false });
+		const spinner = page.getByRole('status');
+		await expect.element(spinner).not.toBeInTheDocument();
+	});
+
+	it('shows spinner and hides search icon when isLoading is true', async () => {
+		render(SearchFilterBar, { ...defaultProps, sort: 'DATE', dir: 'desc', isLoading: true });
+		const spinner = page.getByRole('status');
+		await expect.element(spinner).toBeInTheDocument();
+	});
+});
+
 describe('SearchFilterBar – tagQ live filter', () => {
 	it('calls onSearch when tag text changes in TagInput', async () => {
 		vi.stubGlobal(

frontend/src/routes/page.svelte.spec.ts

@@ -240,6 +240,16 @@ describe('Home page – error state', () => {
 	});
 });
 
+// ─── Loading spinner ──────────────────────────────────────────────────────────
+
+describe('Home page – loading spinner', () => {
+	it('does not show spinner by default', async () => {
+		render(Page, { data: emptyData });
+		const spinner = page.getByRole('status');
+		await expect.element(spinner).not.toBeInTheDocument();
+	});
+});
+
 // ─── Sort controls ────────────────────────────────────────────────────────────
 
 describe('Home page – sort controls', () => {