refactor(document): extract shared DocumentOption type and createDocumentTypeahead factory

DocumentPickerDropdown and DocumentMultiSelect had identical createTypeahead
configs, fetch logic, and formatDocLabel helpers. Extracted to
documentTypeahead.ts; all four consumers import from the shared module.

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

frontend/src/lib/document/DocumentMultiSelect.svelte

@@ -1,22 +1,11 @@
 <script lang="ts">
-import type { components } from '$lib/generated/api';
 import { m } from '$lib/paraglide/messages.js';
 import { clickOutside } from '$lib/shared/actions/clickOutside';
-import { createTypeahead } from '$lib/shared/hooks/useTypeahead.svelte';
-import { formatDocumentDate, type DatePrecision } from '$lib/shared/utils/documentDate';
-import { getLocale } from '$lib/paraglide/runtime.js';
-
-type DocumentListItem = components['schemas']['DocumentListItem'];
-
-/**
- * Exactly the fields this picker reads — id for selection/dedup, the rest for
- * the honest date label. A full `Document` and a `DocumentListItem` are both
- * structurally assignable, so the search results need no cast.
- */
-type DocumentOption = Pick<
-	DocumentListItem,
-	'id' | 'title' | 'documentDate' | 'metaDatePrecision' | 'metaDateEnd'
->;
+import {
+	createDocumentTypeahead,
+	formatDocumentOption,
+	type DocumentOption
+} from './documentTypeahead';
 
 interface Props {
 	selectedDocuments?: DocumentOption[];
@@ -34,20 +23,7 @@ let searchTerm = $state('');
 let inputEl: HTMLInputElement;
 let dropdownStyle = $state('');
 
-const picker = createTypeahead<DocumentOption>({
-	fetchUrl: (q) =>
-		fetch(`/api/documents/search?q=${encodeURIComponent(q)}&size=10`)
-			.then((r) => r.json())
-			.then((b: { items: DocumentListItem[] }) =>
-				b.items.map((it) => ({
-					id: it.id,
-					title: it.title,
-					documentDate: it.documentDate,
-					metaDatePrecision: it.metaDatePrecision,
-					metaDateEnd: it.metaDateEnd
-				}))
-			)
-});
+const picker = createDocumentTypeahead();
 
 // Filter out already-selected documents from typeahead results.
 const filteredResults = $derived(
@@ -77,18 +53,6 @@ function selectDocument(doc: DocumentOption) {
 function removeDocument(id: string | undefined) {
 	selectedDocuments = selectedDocuments.filter((d) => d.id !== id);
 }
-
-function formatDocLabel(doc: DocumentOption): string {
-	if (!doc.documentDate) return doc.title;
-	const label = formatDocumentDate(
-		doc.documentDate,
-		doc.metaDatePrecision as DatePrecision,
-		doc.metaDateEnd,
-		null,
-		getLocale()
-	);
-	return `${doc.title} · ${label}`;
-}
 </script>
 
 <svelte:window onscroll={updateDropdownPosition} onresize={updateDropdownPosition} />
@@ -105,7 +69,7 @@ function formatDocLabel(doc: DocumentOption): string {
 			<span
 				class="inline-flex items-center gap-1 rounded bg-muted px-2 py-1 text-sm font-medium text-ink"
 			>
-				{formatDocLabel(doc)}
+				{formatDocumentOption(doc)}
 				<button
 					type="button"
 					onclick={() => removeDocument(doc.id)}
@@ -152,7 +116,7 @@ function formatDocLabel(doc: DocumentOption): string {
 						role="button"
 						tabindex="0"
 					>
-						{formatDocLabel(doc)}
+						{formatDocumentOption(doc)}
 					</div>
 				{/each}
 			{/if}

frontend/src/lib/document/DocumentPickerDropdown.svelte

@@ -1,16 +1,11 @@
 <script lang="ts">
-import type { components } from '$lib/generated/api';
 import { m } from '$lib/paraglide/messages.js';
 import { clickOutside } from '$lib/shared/actions/clickOutside';
-import { createTypeahead } from '$lib/shared/hooks/useTypeahead.svelte';
-import { formatDocumentDate, type DatePrecision } from '$lib/shared/utils/documentDate';
-import { getLocale } from '$lib/paraglide/runtime.js';
-
-type DocumentListItem = components['schemas']['DocumentListItem'];
-type DocumentOption = Pick<
-	DocumentListItem,
-	'id' | 'title' | 'documentDate' | 'metaDatePrecision' | 'metaDateEnd'
->;
+import {
+	createDocumentTypeahead,
+	formatDocumentOption,
+	type DocumentOption
+} from './documentTypeahead';
 
 interface Props {
 	alreadyAddedIds?: Set<string>;
@@ -26,20 +21,7 @@ let {
 
 const listboxId = 'doc-picker-listbox';
 
-const picker = createTypeahead<DocumentOption>({
-	fetchUrl: (q) =>
-		fetch(`/api/documents/search?q=${encodeURIComponent(q)}&size=10`)
-			.then((r) => r.json())
-			.then((b: { items: DocumentListItem[] }) =>
-				b.items.map((it) => ({
-					id: it.id,
-					title: it.title,
-					documentDate: it.documentDate,
-					metaDatePrecision: it.metaDatePrecision,
-					metaDateEnd: it.metaDateEnd
-				}))
-			)
-});
+const picker = createDocumentTypeahead();
 
 let inputValue = $state('');
 
@@ -59,18 +41,6 @@ function handleSelect(doc: DocumentOption) {
 	picker.close();
 	onSelect(doc);
 }
-
-function formatDocLabel(doc: DocumentOption): string {
-	if (!doc.documentDate) return doc.title;
-	const label = formatDocumentDate(
-		doc.documentDate,
-		doc.metaDatePrecision as DatePrecision,
-		doc.metaDateEnd,
-		null,
-		getLocale()
-	);
-	return `${doc.title} · ${label}`;
-}
 </script>
 
 <div use:clickOutside onclickoutside={() => picker.close()} class="relative">
@@ -113,7 +83,7 @@ function formatDocLabel(doc: DocumentOption): string {
 								: 'cursor-pointer hover:bg-muted focus:bg-muted focus:outline-none'
 						].join(' ')}
 					>
-						{formatDocLabel(doc)}
+						{formatDocumentOption(doc)}
 						{#if disabled}
 							<span class="sr-only">{m.journey_already_added()}</span>
 						{/if}

frontend/src/lib/document/documentTypeahead.ts

@@ -0,0 +1,40 @@
+import type { components } from '$lib/generated/api';
+import { createTypeahead } from '$lib/shared/hooks/useTypeahead.svelte';
+import { formatDocumentDate, type DatePrecision } from '$lib/shared/utils/documentDate';
+import { getLocale } from '$lib/paraglide/runtime.js';
+
+type DocumentListItem = components['schemas']['DocumentListItem'];
+
+export type DocumentOption = Pick<
+	DocumentListItem,
+	'id' | 'title' | 'documentDate' | 'metaDatePrecision' | 'metaDateEnd'
+>;
+
+export function createDocumentTypeahead() {
+	return createTypeahead<DocumentOption>({
+		fetchUrl: (q) =>
+			fetch(`/api/documents/search?q=${encodeURIComponent(q)}&size=10`)
+				.then((r) => r.json())
+				.then((b: { items: DocumentListItem[] }) =>
+					b.items.map((it) => ({
+						id: it.id,
+						title: it.title,
+						documentDate: it.documentDate,
+						metaDatePrecision: it.metaDatePrecision,
+						metaDateEnd: it.metaDateEnd
+					}))
+				)
+	});
+}
+
+export function formatDocumentOption(doc: DocumentOption): string {
+	if (!doc.documentDate) return doc.title;
+	const label = formatDocumentDate(
+		doc.documentDate,
+		doc.metaDatePrecision as DatePrecision,
+		doc.metaDateEnd,
+		null,
+		getLocale()
+	);
+	return `${doc.title} · ${label}`;
+}

frontend/src/lib/geschichte/JourneyAddBar.svelte

@@ -1,13 +1,7 @@
 <script lang="ts">
-import type { components } from '$lib/generated/api';
 import { m } from '$lib/paraglide/messages.js';
 import DocumentPickerDropdown from '$lib/document/DocumentPickerDropdown.svelte';
-
-type DocumentListItem = components['schemas']['DocumentListItem'];
-type DocumentOption = Pick<
-	DocumentListItem,
-	'id' | 'title' | 'documentDate' | 'metaDatePrecision' | 'metaDateEnd'
->;
+import type { DocumentOption } from '$lib/document/documentTypeahead';
 
 interface Props {
 	alreadyAddedIds?: Set<string>;

frontend/src/lib/geschichte/JourneyEditor.svelte

@@ -4,6 +4,7 @@ import { m } from '$lib/paraglide/messages.js';
 import { csrfFetch } from '$lib/shared/cookies';
 import { createBlockDragDrop } from '$lib/document/transcription/useBlockDragDrop.svelte';
 import { createUnsavedWarning } from '$lib/shared/hooks/useUnsavedWarning.svelte';
+import type { DocumentOption } from '$lib/document/documentTypeahead';
 import GeschichteSidebar from './GeschichteSidebar.svelte';
 import JourneyItemRow from './JourneyItemRow.svelte';
 import JourneyAddBar from './JourneyAddBar.svelte';
@@ -11,11 +12,6 @@ import JourneyAddBar from './JourneyAddBar.svelte';
 type GeschichteView = components['schemas']['GeschichteView'];
 type JourneyItemView = components['schemas']['JourneyItemView'];
 type Person = components['schemas']['Person'];
-type DocumentListItem = components['schemas']['DocumentListItem'];
-type DocumentOption = Pick<
-	DocumentListItem,
-	'id' | 'title' | 'documentDate' | 'metaDatePrecision' | 'metaDateEnd'
->;
 
 interface Props {
 	geschichte: GeschichteView;