fix(admin/system): address review concerns in ImportStatusCard

- Remove dead `message` field from both frontend ImportStatus types
  (field is now @JsonIgnore'd on the backend)
- Extract failure message ternary into `$derived` — business logic off
  the template (Felix)
- Add motion-reduce:animate-none to spinner — WCAG 2.1 SC 2.3.3 (Leonie)
- Replace text-green-600 with text-green-800 — WCAG AA contrast 6.1:1
  on bg-green-50 (Leonie)
- Add min-h-[44px] to all three buttons — WCAG 2.2 44px touch target (Leonie)
- Add 6 missing tests: IMPORT_FAILED_INTERNAL path, IDLE state text,
  null importStatus, ontrigger called on DONE/FAILED/IDLE buttons (Sara)

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

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

@@ -11,7 +11,6 @@ let backfillHashesLoading = $state(false);
 type ImportStatus = {
 	state: 'IDLE' | 'RUNNING' | 'DONE' | 'FAILED';
 	statusCode: string;
-	message: string;
 	processed: number;
 	startedAt: string | null;
 };

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

@@ -4,7 +4,6 @@ import { m } from '$lib/paraglide/messages.js';
 type ImportStatus = {
 	state: 'IDLE' | 'RUNNING' | 'DONE' | 'FAILED';
 	statusCode: string;
-	message: string;
 	processed: number;
 	startedAt: string | null;
 };
@@ -16,6 +15,12 @@ let {
 	importStatus: ImportStatus | null;
 	ontrigger: () => void;
 } = $props();
+
+const failureMessage = $derived(
+	importStatus?.statusCode === 'IMPORT_FAILED_NO_SPREADSHEET'
+		? m.admin_system_import_failed_no_spreadsheet()
+		: m.admin_system_import_failed_internal()
+);
 </script>
 
 <div class="rounded-sm border border-line bg-surface p-6 shadow-sm">
@@ -28,7 +33,7 @@ let {
 				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"
+				class="inline-block h-5 w-5 animate-spin rounded-full border-2 border-ink-3 border-t-brand-mint motion-reduce:animate-none"
 			></span>
 			<div>
 				<p class="text-base font-bold text-ink">{importStatus.processed}</p>
@@ -40,28 +45,26 @@ let {
 	{: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">
+			<p class="text-xs font-bold tracking-widest text-green-800 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>
+			<p class="mt-1 text-xs text-green-800">{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"
+			class="min-h-[44px] 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()}
+			{failureMessage}
 		</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"
+			class="min-h-[44px] 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>
@@ -72,7 +75,7 @@ let {
 		<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"
+			class="min-h-[44px] 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>

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

@@ -1,4 +1,4 @@
-import { describe, it } from 'vitest';
+import { describe, it, vi } from 'vitest';
 import { render } from 'vitest-browser-svelte';
 import { expect } from '@vitest/browser/context';
 import ImportStatusCard from './ImportStatusCard.svelte';
@@ -6,7 +6,6 @@ import ImportStatusCard from './ImportStatusCard.svelte';
 type ImportStatus = {
 	state: 'IDLE' | 'RUNNING' | 'DONE' | 'FAILED';
 	statusCode: string;
-	message: string;
 	processed: number;
 	startedAt: string | null;
 };
@@ -14,7 +13,6 @@ type ImportStatus = {
 const makeStatus = (overrides: Partial<ImportStatus> = {}): ImportStatus => ({
 	state: 'IDLE',
 	statusCode: 'IMPORT_IDLE',
-	message: '',
 	processed: 0,
 	startedAt: null,
 	...overrides
@@ -59,8 +57,7 @@ describe('ImportStatusCard', () => {
 			props: {
 				importStatus: makeStatus({
 					state: 'FAILED',
-					statusCode: 'IMPORT_FAILED_NO_SPREADSHEET',
-					message: 'Keine Tabellendatei...'
+					statusCode: 'IMPORT_FAILED_NO_SPREADSHEET'
 				}),
 				ontrigger: () => {}
 			}
@@ -68,4 +65,73 @@ describe('ImportStatusCard', () => {
 
 		await expect.element(getByText('No spreadsheet file found.')).toBeVisible();
 	});
+
+	it('shows internal error message when statusCode is IMPORT_FAILED_INTERNAL', async () => {
+		const { getByText } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'FAILED', statusCode: 'IMPORT_FAILED_INTERNAL' }),
+				ontrigger: () => {}
+			}
+		});
+
+		await expect.element(getByText('Import failed due to an internal error.')).toBeVisible();
+	});
+
+	it('shows idle text when importStatus is non-null and state is IDLE', async () => {
+		const { getByText } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'IDLE', statusCode: 'IMPORT_IDLE' }),
+				ontrigger: () => {}
+			}
+		});
+
+		await expect.element(getByText('No import started.')).toBeVisible();
+	});
+
+	it('shows no spinner when importStatus is null', async () => {
+		render(ImportStatusCard, {
+			props: { importStatus: null, ontrigger: () => {} }
+		});
+
+		expect(document.querySelector('[data-testid="spinner"]')).toBeNull();
+	});
+
+	it('calls ontrigger when retry button is clicked in DONE state', async () => {
+		const ontrigger = vi.fn();
+		const { getByRole } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'DONE', statusCode: 'IMPORT_DONE', processed: 5 }),
+				ontrigger
+			}
+		});
+
+		await getByRole('button').click();
+		expect(ontrigger).toHaveBeenCalledOnce();
+	});
+
+	it('calls ontrigger when retry button is clicked in FAILED state', async () => {
+		const ontrigger = vi.fn();
+		const { getByRole } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'FAILED', statusCode: 'IMPORT_FAILED_INTERNAL' }),
+				ontrigger
+			}
+		});
+
+		await getByRole('button').click();
+		expect(ontrigger).toHaveBeenCalledOnce();
+	});
+
+	it('calls ontrigger when start button is clicked in IDLE state', async () => {
+		const ontrigger = vi.fn();
+		const { getByRole } = render(ImportStatusCard, {
+			props: {
+				importStatus: makeStatus({ state: 'IDLE', statusCode: 'IMPORT_IDLE' }),
+				ontrigger
+			}
+		});
+
+		await getByRole('button').click();
+		expect(ontrigger).toHaveBeenCalledOnce();
+	});
 });