feat(frontend): render honest precision dates in detail, list and search

Wires formatDocumentDate/DocumentDate into the read sites: the document
detail top bar + metadata drawer (the drawer shows the visible "Originaltext:"
raw line for UNKNOWN/SEASON/APPROX), the search/list rows (DocumentRow,
mobile + desktop), and the document multi-select dropdown label. A MONTH or
SEASON document now reads "Juni 1916"/"Sommer 1916" everywhere instead of a
fabricated day.

Adds metaDatePrecision to the DocumentRow/DocumentMultiSelect test fixtures
(required on DocumentListItem since #671) and updates the multi-select label
assertion to the honest long date.

Refs #666

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/lib/document/DocumentMetadataDrawer.svelte

@@ -4,6 +4,8 @@ import { formatDate } from '$lib/shared/utils/date';
 import { formatDocumentStatus } from '$lib/document/documentStatusLabel';
 import { getInitials, personAvatarColor } from '$lib/person/personFormat';
 import RelationshipPill from '$lib/person/relationship/RelationshipPill.svelte';
+import DocumentDate from './DocumentDate.svelte';
+import type { DatePrecision } from '$lib/shared/utils/documentDate';
 
 type Person = { id: string; firstName?: string | null; lastName: string; displayName: string };
 type Tag = { id: string; name: string };
@@ -16,6 +18,9 @@ type GeschichteSummary = {
 
 type Props = {
 	documentDate: string | null;
+	metaDatePrecision?: DatePrecision | null;
+	metaDateEnd?: string | null;
+	metaDateRaw?: string | null;
 	location: string | null;
 	status: string;
 	sender: Person | null;
@@ -29,6 +34,9 @@ type Props = {
 
 let {
 	documentDate,
+	metaDatePrecision = null,
+	metaDateEnd = null,
+	metaDateRaw = null,
 	location,
 	status,
 	sender,
@@ -59,7 +67,6 @@ function formatGeschichteDate(g: GeschichteSummary): string {
 	return formatDate(g.publishedAt.slice(0, 10), 'short');
 }
 
-const formattedDate = $derived(documentDate ? formatDate(documentDate) : '—');
 const displayLocation = $derived(location ?? '—');
 const statusLabel = $derived(formatDocumentStatus(status));
 const visibleReceivers = $derived(receivers.slice(0, VISIBLE_RECEIVER_LIMIT));
@@ -105,7 +112,18 @@ function getFullName(person: Person): string {
 			<dl class="space-y-3 font-serif text-sm">
 				<div>
 					<dt class="font-sans text-xs font-medium text-ink-3">{m.doc_details_field_date()}</dt>
-					<dd class="text-ink">{formattedDate}</dd>
+					<dd class="text-ink">
+						{#if documentDate || metaDateRaw}
+							<DocumentDate
+								iso={documentDate}
+								precision={metaDatePrecision}
+								end={metaDateEnd}
+								raw={metaDateRaw}
+							/>
+						{:else}
+							—
+						{/if}
+					</dd>
 				</div>
 				<div>
 					<dt class="font-sans text-xs font-medium text-ink-3">{m.form_label_location()}</dt>