refactor(#240): deduplicate formatDate, use generated types, always-visible strip

- Add formatMCDate() to $lib/utils/date.ts (locale-aware, medium format);
  remove duplicated inline formatDate() from all three column components
- Replace local TranscriptionQueueItemDTO/TranscriptionWeeklyStatsDTO type
  declarations with imports from $lib/generated/api across all four components
- Add dashed empty states to SegmentationColumn and TranscriptionColumn
  (ReadyColumn already had one)
- Remove outer {#if} from MissionControlStrip so the section is always
  visible — each column owns its own empty state

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

frontend/src/lib/components/MissionControlStrip.svelte

@@ -1,23 +1,12 @@
 <script lang="ts">
 import * as m from '$lib/paraglide/messages.js';
+import type { components } from '$lib/generated/api';
 import SegmentationColumn from './SegmentationColumn.svelte';
 import TranscriptionColumn from './TranscriptionColumn.svelte';
 import ReadyColumn from './ReadyColumn.svelte';
 
-type TranscriptionQueueItemDTO = {
+type TranscriptionQueueItemDTO = components['schemas']['TranscriptionQueueItemDTO'];
-	id: string;
+type TranscriptionWeeklyStatsDTO = components['schemas']['TranscriptionWeeklyStatsDTO'];
-	title: string;
-	documentDate?: string;
-	annotationCount: number;
-	textedBlockCount: number;
-	reviewedBlockCount: number;
-};
-
-type TranscriptionWeeklyStatsDTO = {
-	segmentationCount: number;
-	transcriptionCount: number;
-	readyCount: number;
-};
 
 interface Props {
 	segmentationDocs: TranscriptionQueueItemDTO[];
@@ -29,21 +18,16 @@ interface Props {
 let { segmentationDocs, transcriptionDocs, readyDocs, weeklyStats }: Props = $props();
 </script>
 
-{#if segmentationDocs.length > 0 || transcriptionDocs.length > 0 || readyDocs.length > 0}
+<section class="mt-4 rounded-sm border border-line bg-surface p-6">
-	<section class="mt-4 rounded-sm border border-line bg-surface p-6">
+	<h2 class="mb-4 font-sans text-xs font-bold tracking-widest text-ink-3 uppercase">
-		<h2 class="mb-4 font-sans text-xs font-bold tracking-widest text-ink-3 uppercase">
+		{m.mission_control_heading()}
-			{m.mission_control_heading()}
+	</h2>
-		</h2>
+	<div class="grid grid-cols-1 gap-4 sm:grid-cols-3">
-		<div class="grid grid-cols-1 gap-4 sm:grid-cols-3">
+		<SegmentationColumn docs={segmentationDocs} weeklyCount={weeklyStats?.segmentationCount ?? 0} />
-			<SegmentationColumn
+		<TranscriptionColumn
-				docs={segmentationDocs}
+			docs={transcriptionDocs}
-				weeklyCount={weeklyStats?.segmentationCount ?? 0}
+			weeklyCount={weeklyStats?.transcriptionCount ?? 0}
-			/>
+		/>
-			<TranscriptionColumn
+		<ReadyColumn docs={readyDocs} weeklyCount={weeklyStats?.readyCount ?? 0} />
-				docs={transcriptionDocs}
+	</div>
-				weeklyCount={weeklyStats?.transcriptionCount ?? 0}
+</section>
-			/>
-			<ReadyColumn docs={readyDocs} weeklyCount={weeklyStats?.readyCount ?? 0} />
-		</div>
-	</section>
-{/if}

frontend/src/lib/components/ReadyColumn.svelte

@@ -1,15 +1,10 @@
 <script lang="ts">
 import * as m from '$lib/paraglide/messages.js';
 import { getLocale } from '$lib/paraglide/runtime.js';
+import { formatMCDate } from '$lib/utils/date.js';
+import type { components } from '$lib/generated/api';
 
-type TranscriptionQueueItemDTO = {
+type TranscriptionQueueItemDTO = components['schemas']['TranscriptionQueueItemDTO'];
-	id: string;
-	title: string;
-	documentDate?: string;
-	annotationCount: number;
-	textedBlockCount: number;
-	reviewedBlockCount: number;
-};
 
 interface Props {
 	docs: TranscriptionQueueItemDTO[];
@@ -18,14 +13,6 @@ interface Props {
 
 let { docs, weeklyCount }: Props = $props();
 
-function formatDate(dateStr: string): string {
-	return new Intl.DateTimeFormat(getLocale(), {
-		day: 'numeric',
-		month: 'short',
-		year: 'numeric'
-	}).format(new Date(dateStr + 'T12:00:00'));
-}
-
 function reviewedPct(doc: TranscriptionQueueItemDTO): number {
 	if (doc.annotationCount === 0) return 0;
 	return Math.round((doc.reviewedBlockCount / doc.annotationCount) * 100);
@@ -61,7 +48,8 @@ function reviewedPct(doc: TranscriptionQueueItemDTO): number {
 						<span class="font-serif text-sm text-ink">{doc.title}</span>
 						<div class="mt-0.5 flex items-center gap-2">
 							{#if doc.documentDate}
-								<span class="text-xs text-ink-3">{formatDate(doc.documentDate)}</span>
+								<span class="text-xs text-ink-3">{formatMCDate(doc.documentDate, getLocale())}</span
+								>
 							{/if}
 							{#if doc.textedBlockCount > 0}
 								<span class="text-xs font-semibold text-ink">

frontend/src/lib/components/SegmentationColumn.svelte

@@ -1,15 +1,10 @@
 <script lang="ts">
 import * as m from '$lib/paraglide/messages.js';
 import { getLocale } from '$lib/paraglide/runtime.js';
+import { formatMCDate } from '$lib/utils/date.js';
+import type { components } from '$lib/generated/api';
 
-type TranscriptionQueueItemDTO = {
+type TranscriptionQueueItemDTO = components['schemas']['TranscriptionQueueItemDTO'];
-	id: string;
-	title: string;
-	documentDate?: string;
-	annotationCount: number;
-	textedBlockCount: number;
-	reviewedBlockCount: number;
-};
 
 interface Props {
 	docs: TranscriptionQueueItemDTO[];
@@ -17,14 +12,6 @@ interface Props {
 }
 
 let { docs, weeklyCount }: Props = $props();
-
-function formatDate(dateStr: string): string {
-	return new Intl.DateTimeFormat(getLocale(), {
-		day: 'numeric',
-		month: 'short',
-		year: 'numeric'
-	}).format(new Date(dateStr + 'T12:00:00'));
-}
 </script>
 
 {#if docs.length > 0}
@@ -53,11 +40,19 @@ function formatDate(dateStr: string): string {
 					>
 						<span class="font-serif text-sm text-ink">{doc.title}</span>
 						{#if doc.documentDate}
-							<span class="mt-0.5 text-xs text-ink-3">{formatDate(doc.documentDate)}</span>
+							<span class="mt-0.5 text-xs text-ink-3"
+								>{formatMCDate(doc.documentDate, getLocale())}</span
+							>
 						{/if}
 					</a>
 				</li>
 			{/each}
 		</ul>
 	</div>
+{:else}
+	<div
+		class="flex min-h-[120px] flex-col items-center justify-center rounded-sm border border-dashed border-line bg-surface/50 p-6 text-center"
+	>
+		<p class="text-xs text-ink-3">{m.mission_control_segmentation_empty()}</p>
+	</div>
 {/if}

frontend/src/lib/components/TranscriptionColumn.svelte

@@ -1,15 +1,10 @@
 <script lang="ts">
 import * as m from '$lib/paraglide/messages.js';
 import { getLocale } from '$lib/paraglide/runtime.js';
+import { formatMCDate } from '$lib/utils/date.js';
+import type { components } from '$lib/generated/api';
 
-type TranscriptionQueueItemDTO = {
+type TranscriptionQueueItemDTO = components['schemas']['TranscriptionQueueItemDTO'];
-	id: string;
-	title: string;
-	documentDate?: string;
-	annotationCount: number;
-	textedBlockCount: number;
-	reviewedBlockCount: number;
-};
 
 interface Props {
 	docs: TranscriptionQueueItemDTO[];
@@ -18,14 +13,6 @@ interface Props {
 
 let { docs, weeklyCount }: Props = $props();
 
-function formatDate(dateStr: string): string {
-	return new Intl.DateTimeFormat(getLocale(), {
-		day: 'numeric',
-		month: 'short',
-		year: 'numeric'
-	}).format(new Date(dateStr + 'T12:00:00'));
-}
-
 function blockProgress(doc: TranscriptionQueueItemDTO): number {
 	if (doc.annotationCount === 0) return 0;
 	return (doc.textedBlockCount / doc.annotationCount) * 100;
@@ -58,7 +45,9 @@ function blockProgress(doc: TranscriptionQueueItemDTO): number {
 					>
 						<span class="font-serif text-sm text-ink">{doc.title}</span>
 						{#if doc.documentDate}
-							<span class="mt-0.5 text-xs text-ink-3">{formatDate(doc.documentDate)}</span>
+							<span class="mt-0.5 text-xs text-ink-3"
+								>{formatMCDate(doc.documentDate, getLocale())}</span
+							>
 						{/if}
 						{#if doc.textedBlockCount > 0}
 							<div class="mt-1.5 flex items-center gap-2">
@@ -83,4 +72,10 @@ function blockProgress(doc: TranscriptionQueueItemDTO): number {
 			{/each}
 		</ul>
 	</div>
+{:else}
+	<div
+		class="flex min-h-[120px] flex-col items-center justify-center rounded-sm border border-dashed border-line bg-surface/50 p-6 text-center"
+	>
+		<p class="text-xs text-ink-3">{m.mission_control_transcription_empty()}</p>
+	</div>
 {/if}

frontend/src/lib/utils/date.ts

@@ -19,6 +19,19 @@ export function formatDate(isoDate: string, format: 'short' | 'long' = 'long'):
 	}).format(date);
 }
 
+/**
+ * Format an ISO date string for medium-length display (e.g. "15. Jun. 1920").
+ * Uses T12:00:00 to avoid UTC timezone off-by-one.
+ * Pass an explicit BCP 47 locale tag to respect the app locale; defaults to 'de-DE'.
+ */
+export function formatMCDate(isoDate: string, locale: string = 'de-DE'): string {
+	return new Intl.DateTimeFormat(locale, {
+		day: 'numeric',
+		month: 'short',
+		year: 'numeric'
+	}).format(new Date(isoDate + 'T12:00:00'));
+}
+
 /**
  * Converts an ISO date string (YYYY-MM-DD) to German display format (DD.MM.YYYY).
  * Returns an empty string for invalid or empty input.