feat(admin): add OCR training card to admin/system page

- TrainingHistory.svelte: responsive table with status badges
  (green/red/animated pulse), keyed iteration, empty-state row
- OcrTrainingCard.svelte: shows available blocks/docs, disabled states
  (< 5 blocks, service down), in-flight "…" state, 5s success message,
  embeds TrainingHistory
- Wired into admin/system/+page.svelte via fetchTrainingInfo() in $effect
- Regenerated api.ts with OcrTrainingRun + TrainingInfoResponse types
- TRAINING_ALREADY_RUNNING error code in errors.ts + de/en/es translations
- 7 OcrTrainingCard Vitest tests

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

frontend/src/lib/components/TrainingHistory.svelte

@@ -0,0 +1,76 @@
+<script lang="ts">
+interface Run {
+	id: string;
+	status: 'RUNNING' | 'DONE' | 'FAILED';
+	blockCount: number;
+	documentCount: number;
+	modelName: string;
+	errorMessage?: string;
+	triggeredBy?: string;
+	createdAt: string;
+	completedAt?: string;
+}
+
+interface Props {
+	runs: Run[];
+}
+
+let { runs }: Props = $props();
+
+const dateFormatter = new Intl.DateTimeFormat('de-DE', {
+	day: 'numeric',
+	month: 'short',
+	year: 'numeric'
+});
+
+function formatDate(iso: string): string {
+	return dateFormatter.format(new Date(iso));
+}
+</script>
+
+<table class="w-full text-sm">
+	<thead>
+		<tr class="border-b border-line text-xs font-bold tracking-widest text-ink-3 uppercase">
+			<th class="pb-2 text-left">Datum</th>
+			<th class="pb-2 text-left">Status</th>
+			<th class="pb-2 text-right">Blöcke</th>
+			<th class="hidden pb-2 text-right md:table-cell">Dokumente</th>
+		</tr>
+	</thead>
+	<tbody>
+		{#if runs.length === 0}
+			<tr>
+				<td colspan="4" class="py-4 text-center text-sm text-ink-2">
+					Noch keine Trainings-Läufe.
+				</td>
+			</tr>
+		{:else}
+			{#each runs as run (run.id)}
+				<tr class="border-b border-line/50 last:border-0">
+					<td class="py-2 text-ink-2">{formatDate(run.createdAt)}</td>
+					<td class="py-2">
+						{#if run.status === 'DONE'}
+							<span
+								class="inline-flex items-center gap-1 rounded-sm bg-green-100 px-1.5 py-0.5 text-xs font-medium text-green-700"
+								>✓ Fertig</span
+							>
+						{:else if run.status === 'FAILED'}
+							<span
+								class="inline-flex items-center gap-1 rounded-sm bg-red-100 px-1.5 py-0.5 text-xs font-medium text-red-700"
+								title={run.errorMessage}>✗ Fehler</span
+							>
+						{:else}
+							<span
+								class="inline-flex items-center gap-1 rounded-sm bg-yellow-100 px-1.5 py-0.5 text-xs font-medium text-yellow-700"
+								><span class="h-1.5 w-1.5 animate-pulse rounded-full bg-yellow-500"
+								></span>Läuft…</span
+							>
+						{/if}
+					</td>
+					<td class="py-2 text-right text-ink-2">{run.blockCount}</td>
+					<td class="hidden py-2 text-right text-ink-2 md:table-cell">{run.documentCount}</td>
+				</tr>
+			{/each}
+		{/if}
+	</tbody>
+</table>