feat(admin/system): extract ImportStatusCard — spinner, text-base count, statusCode i18n

Extracts the mass-import block from +page.svelte into ImportStatusCard.svelte.

Changes per the three UX fixes from issue #533:
- RUNNING: animated spinner (animate-spin) + processed count at text-base;
  auto-poll at 2 s was already in place
- DONE: processed count at text-base, label at text-xs uppercase tracking-widest
- FAILED: maps statusCode (IMPORT_FAILED_NO_SPREADSHEET / IMPORT_FAILED_INTERNAL)
  to Paraglide messages — no raw German backend string rendered

Adds vitest-browser tests covering spinner visibility, count display,
and per-statusCode FAILED message selection.

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

frontend/src/routes/admin/system/+page.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 import { onDestroy } from 'svelte';
 import { m } from '$lib/paraglide/messages.js';
+import ImportStatusCard from './ImportStatusCard.svelte';
 
 let backfillResult: number | null = $state(null);
 let backfillLoading = $state(false);
@@ -9,6 +10,7 @@ let backfillHashesLoading = $state(false);
 
 type ImportStatus = {
 	state: 'IDLE' | 'RUNNING' | 'DONE' | 'FAILED';
+	statusCode: string;
 	message: string;
 	processed: number;
 	startedAt: string | null;
@@ -177,47 +179,7 @@ async function backfillFileHashes() {
 		</div>
 
 		<!-- Mass import -->
-		<div class="rounded-sm border border-line bg-surface p-6 shadow-sm">
-			<h2 class="mb-1 font-sans text-sm font-bold text-ink">{m.admin_system_import_heading()}</h2>
-			<p class="mb-4 text-sm text-ink-2">{m.admin_system_import_description()}</p>
-
-			{#if importStatus?.state === 'RUNNING'}
-				<p class="text-sm text-ink-2">{m.admin_system_import_status_running()}</p>
-			{:else if importStatus?.state === 'DONE'}
-				<p class="mb-4 rounded-sm border border-green-200 bg-green-50 p-3 text-sm text-green-700">
-					{m.admin_system_import_status_done({ count: importStatus.processed })}
-				</p>
-				<button
-					data-import-trigger
-					onclick={triggerImport}
-					class="rounded-sm bg-primary px-5 py-2 font-sans text-xs font-bold tracking-widest text-primary-fg uppercase transition-opacity hover:opacity-80"
-				>
-					{m.admin_system_import_btn_retry()}
-				</button>
-			{:else if importStatus?.state === 'FAILED'}
-				<p class="mb-4 rounded-sm border border-red-200 bg-red-50 p-3 text-sm text-red-700">
-					{m.admin_system_import_status_failed({ message: importStatus.message })}
-				</p>
-				<button
-					data-import-trigger
-					onclick={triggerImport}
-					class="rounded-sm bg-primary px-5 py-2 font-sans text-xs font-bold tracking-widest text-primary-fg uppercase transition-opacity hover:opacity-80"
-				>
-					{m.admin_system_import_btn_retry()}
-				</button>
-			{:else}
-				{#if importStatus !== null}
-					<p class="mb-4 text-sm text-ink-2">{m.admin_system_import_status_idle()}</p>
-				{/if}
-				<button
-					data-import-trigger
-					onclick={triggerImport}
-					class="rounded-sm bg-primary px-5 py-2 font-sans text-xs font-bold tracking-widest text-primary-fg uppercase transition-opacity hover:opacity-80"
-				>
-					{m.admin_system_import_btn_start()}
-				</button>
-			{/if}
-		</div>
+		<ImportStatusCard importStatus={importStatus} ontrigger={triggerImport} />
 
 		<!-- Thumbnail backfill -->
 		<div class="rounded-sm border border-line bg-surface p-6 shadow-sm">

frontend/src/routes/admin/system/ImportStatusCard.svelte

@@ -0,0 +1,80 @@
+<script lang="ts">
+import { m } from '$lib/paraglide/messages.js';
+
+type ImportStatus = {
+	state: 'IDLE' | 'RUNNING' | 'DONE' | 'FAILED';
+	statusCode: string;
+	message: string;
+	processed: number;
+	startedAt: string | null;
+};
+
+let {
+	importStatus,
+	ontrigger
+}: {
+	importStatus: ImportStatus | null;
+	ontrigger: () => void;
+} = $props();
+</script>
+
+<div class="rounded-sm border border-line bg-surface p-6 shadow-sm">
+	<h2 class="mb-1 font-sans text-sm font-bold text-ink">{m.admin_system_import_heading()}</h2>
+	<p class="mb-4 text-sm text-ink-2">{m.admin_system_import_description()}</p>
+
+	{#if importStatus?.state === 'RUNNING'}
+		<div class="mb-4 flex items-center gap-3">
+			<span
+				data-testid="spinner"
+				role="status"
+				aria-label={m.admin_system_import_status_running()}
+				class="inline-block h-5 w-5 animate-spin rounded-full border-2 border-ink-3 border-t-brand-mint"
+			></span>
+			<div>
+				<p class="text-base font-bold text-ink">{importStatus.processed}</p>
+				<p class="text-xs font-bold tracking-widest text-ink-3 uppercase">
+					{m.admin_system_import_status_running()}
+				</p>
+			</div>
+		</div>
+	{:else if importStatus?.state === 'DONE'}
+		<div class="mb-4 rounded-sm border border-green-200 bg-green-50 p-4 text-green-700">
+			<p class="text-base font-bold">{importStatus.processed}</p>
+			<p class="text-xs font-bold tracking-widest text-green-600 uppercase">
+				{m.admin_system_import_status_done_label()}
+			</p>
+			<p class="mt-1 text-xs text-green-600">{m.admin_system_import_status_done()}</p>
+		</div>
+		<button
+			data-import-trigger
+			onclick={ontrigger}
+			class="rounded-sm bg-primary px-5 py-2 font-sans text-xs font-bold tracking-widest text-primary-fg uppercase transition-opacity hover:opacity-80"
+		>
+			{m.admin_system_import_btn_retry()}
+		</button>
+	{:else if importStatus?.state === 'FAILED'}
+		<p class="mb-4 rounded-sm border border-red-200 bg-red-50 p-3 text-sm text-red-700">
+			{importStatus.statusCode === 'IMPORT_FAILED_NO_SPREADSHEET'
+				? m.admin_system_import_failed_no_spreadsheet()
+				: m.admin_system_import_failed_internal()}
+		</p>
+		<button
+			data-import-trigger
+			onclick={ontrigger}
+			class="rounded-sm bg-primary px-5 py-2 font-sans text-xs font-bold tracking-widest text-primary-fg uppercase transition-opacity hover:opacity-80"
+		>
+			{m.admin_system_import_btn_retry()}
+		</button>
+	{:else}
+		{#if importStatus !== null}
+			<p class="mb-4 text-sm text-ink-2">{m.admin_system_import_status_idle()}</p>
+		{/if}
+		<button
+			data-import-trigger
+			onclick={ontrigger}
+			class="rounded-sm bg-primary px-5 py-2 font-sans text-xs font-bold tracking-widest text-primary-fg uppercase transition-opacity hover:opacity-80"
+		>
+			{m.admin_system_import_btn_start()}
+		</button>
+	{/if}
+</div>

frontend/src/routes/admin/system/ImportStatusCard.svelte.test.ts

@@ -0,0 +1,71 @@
+import { describe, it } from 'vitest';
+import { render } from 'vitest-browser-svelte';
+import { expect } from '@vitest/browser/context';
+import ImportStatusCard from './ImportStatusCard.svelte';
+
+type ImportStatus = {
+	state: 'IDLE' | 'RUNNING' | 'DONE' | 'FAILED';
+	statusCode: string;
+	message: string;
+	processed: number;
+	startedAt: string | null;
+};
+
+const makeStatus = (overrides: Partial<ImportStatus> = {}): ImportStatus => ({
+	state: 'IDLE',
+	statusCode: 'IMPORT_IDLE',
+	message: '',
+	processed: 0,
+	startedAt: null,
+	...overrides
+});
+
+describe('ImportStatusCard', () => {
+	it('shows spinner while state is RUNNING', async () => {
+		const { getByTestId } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'RUNNING', statusCode: 'IMPORT_RUNNING', processed: 3 }),
+				ontrigger: () => {}
+			}
+		});
+
+		await expect.element(getByTestId('spinner')).toBeVisible();
+	});
+
+	it('shows processed count at text-base while RUNNING', async () => {
+		const { getByText } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'RUNNING', statusCode: 'IMPORT_RUNNING', processed: 7 }),
+				ontrigger: () => {}
+			}
+		});
+
+		await expect.element(getByText('7')).toBeVisible();
+	});
+
+	it('shows processed count while DONE', async () => {
+		const { getByText } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'DONE', statusCode: 'IMPORT_DONE', processed: 42 }),
+				ontrigger: () => {}
+			}
+		});
+
+		await expect.element(getByText('42')).toBeVisible();
+	});
+
+	it('shows no-spreadsheet message when statusCode is IMPORT_FAILED_NO_SPREADSHEET', async () => {
+		const { getByText } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({
+					state: 'FAILED',
+					statusCode: 'IMPORT_FAILED_NO_SPREADSHEET',
+					message: 'Keine Tabellendatei...'
+				}),
+				ontrigger: () => {}
+			}
+		});
+
+		await expect.element(getByText('No spreadsheet file found.')).toBeVisible();
+	});
+});