refactor: move document domain core to lib/document/

Moves ~25 components, utils (search, filename, groupDocuments,
documentStatusLabel, validateFile), bulkSelection store, and
TranscriptionSection sub-component. Fixes broken relative imports.

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

frontend/src/lib/document/DashboardNeedsMetadata.svelte

@@ -0,0 +1,73 @@
+<script lang="ts">
+import * as m from '$lib/paraglide/messages.js';
+import { relativeTimeDe } from '$lib/relativeTime';
+
+type IncompleteDoc = {
+	id: string;
+	title: string;
+	uploadedAt: string;
+};
+
+interface Props {
+	topDocs: IncompleteDoc[];
+	totalCount: number;
+}
+
+let { topDocs, totalCount }: Props = $props();
+
+const showFooter = $derived(totalCount > 5);
+</script>
+
+{#if topDocs.length > 0}
+	<div data-testid="dashboard-needs-metadata" class="rounded-sm border border-line bg-surface p-6">
+		<h2 class="mb-4 font-sans text-xs font-bold tracking-widest text-gray-400 uppercase">
+			{m.dashboard_needs_metadata_heading()}
+		</h2>
+		<ul class="divide-y divide-line">
+			{#each topDocs as doc (doc.id)}
+				<li>
+					<a
+						href="/enrich/{doc.id}"
+						class="group flex items-center gap-3 py-3 text-ink hover:bg-accent-bg/40"
+					>
+						<img
+							src="/degruyter-icons/Simple/Medium-24px/SVG/Action/Copy-Item-MD.svg"
+							alt=""
+							aria-hidden="true"
+							class="h-5 w-5 shrink-0 opacity-50 group-hover:opacity-80"
+						/>
+						<div class="min-w-0 flex-1">
+							<div class="truncate font-serif text-base text-ink group-hover:underline">
+								<span class="sr-only">PDF: </span>{doc.title}
+							</div>
+							<div class="font-sans text-xs text-ink-3">
+								{relativeTimeDe(new Date(doc.uploadedAt))}
+							</div>
+						</div>
+						<svg
+							class="h-4 w-4 shrink-0 text-ink-3 transition-transform group-hover:translate-x-0.5 motion-reduce:transition-none motion-reduce:group-hover:translate-x-0"
+							xmlns="http://www.w3.org/2000/svg"
+							fill="none"
+							viewBox="0 0 24 24"
+							stroke="currentColor"
+							stroke-width="2"
+							aria-hidden="true"
+						>
+							<path stroke-linecap="round" stroke-linejoin="round" d="M9 5l7 7-7 7" />
+						</svg>
+					</a>
+				</li>
+			{/each}
+		</ul>
+		{#if showFooter}
+			<div class="mt-4">
+				<a
+					href="/enrich"
+					class="font-sans text-sm font-medium text-ink-2 hover:text-ink hover:underline"
+				>
+					{m.dashboard_needs_metadata_show_all_count({ count: totalCount })}
+				</a>
+			</div>
+		{/if}
+	</div>
+{/if}