feat(journey-editor): build DocumentPickerDropdown + refactor DocumentMultiSelect

New DocumentPickerDropdown: single-select document search with aria-disabled
for already-added items and sr-only "bereits enthalten" hint. DocumentMultiSelect
refactored to use createTypeahead, removing raw setTimeout/debounceTimer.

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

frontend/src/lib/document/DocumentMultiSelect.svelte

@@ -2,6 +2,7 @@
 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';
 
@@ -30,13 +31,29 @@ let {
 }: Props = $props();
 
 let searchTerm = $state('');
-let results: DocumentOption[] = $state([]);
-let showDropdown = $state(false);
-let loading = $state(false);
-let debounceTimer: ReturnType<typeof setTimeout>;
 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
+				}))
+			)
+});
+
+// Filter out already-selected documents from typeahead results.
+const filteredResults = $derived(
+	picker.results.filter((d) => !selectedDocuments.some((s) => s.id === d.id))
+);
+
 function updateDropdownPosition() {
 	if (!inputEl) return;
 	const rect = inputEl.getBoundingClientRect();
@@ -44,40 +61,17 @@ function updateDropdownPosition() {
 }
 
 function handleInput() {
-	showDropdown = true;
-	clearTimeout(debounceTimer);
-	debounceTimer = setTimeout(async () => {
-		if (searchTerm.length < 1) {
-			results = [];
-			return;
-		}
-		loading = true;
-		try {
-			const res = await fetch(`/api/documents/search?q=${encodeURIComponent(searchTerm)}&size=10`);
-			if (res.ok) {
-				const body: { items: DocumentListItem[] } = await res.json();
-				const docs: DocumentOption[] = body.items.map((it) => ({
-					id: it.id,
-					title: it.title,
-					documentDate: it.documentDate,
-					metaDatePrecision: it.metaDatePrecision,
-					metaDateEnd: it.metaDateEnd
-				}));
-				results = docs.filter((d) => !selectedDocuments.some((s) => s.id === d.id));
-			}
-		} catch {
-			results = [];
-		} finally {
-			loading = false;
-		}
-	}, 300);
+	if (searchTerm.trim().length >= 1) {
+		picker.setQuery(searchTerm);
+	} else {
+		picker.close();
+	}
 }
 
 function selectDocument(doc: DocumentOption) {
 	selectedDocuments = [...selectedDocuments, doc];
 	searchTerm = '';
-	showDropdown = false;
-	results = [];
+	picker.close();
 }
 
 function removeDocument(id: string | undefined) {
@@ -103,7 +97,7 @@ function formatDocLabel(doc: DocumentOption): string {
 	<input type="hidden" name={hiddenInputName} value={doc.id} />
 {/each}
 
-<div class="relative" use:clickOutside onclickoutside={() => (showDropdown = false)}>
+<div class="relative" use:clickOutside onclickoutside={() => picker.close()}>
 	<div
 		class="flex min-h-[38px] flex-wrap gap-2 rounded border border-line bg-surface p-2 shadow-sm focus-within:ring-2 focus-within:ring-focus-ring focus-within:outline-none"
 	>
@@ -136,24 +130,21 @@ function formatDocLabel(doc: DocumentOption): string {
 			autocomplete="off"
 			bind:value={searchTerm}
 			oninput={handleInput}
-			onfocus={() => {
-				updateDropdownPosition();
-				showDropdown = true;
-			}}
+			onfocus={() => updateDropdownPosition()}
 			placeholder={placeholder}
 			class="min-w-[120px] flex-1 border-none bg-transparent p-1 text-sm outline-none focus:ring-0"
 		/>
 	</div>
 
-	{#if showDropdown && (results.length > 0 || loading)}
+	{#if picker.isOpen && (filteredResults.length > 0 || picker.loading)}
 		<div
 			style={dropdownStyle}
 			class="ring-opacity-5 z-50 max-h-60 overflow-auto rounded-md bg-surface py-1 text-base shadow-lg ring-1 ring-black sm:text-sm"
 		>
-			{#if loading}
+			{#if picker.loading}
 				<div class="p-2 text-sm text-ink-2">{m.comp_multiselect_loading()}</div>
 			{:else}
-				{#each results as doc (doc.id)}
+				{#each filteredResults as doc (doc.id)}
 					<div
 						class="cursor-pointer py-2 pr-9 pl-3 text-ink select-none hover:bg-muted"
 						onclick={() => selectDocument(doc)}

frontend/src/lib/document/DocumentPickerDropdown.svelte

@@ -0,0 +1,124 @@
+<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'
+>;
+
+interface Props {
+	alreadyAddedIds?: Set<string>;
+	placeholder?: string;
+	onSelect: (doc: DocumentOption) => void;
+}
+
+let {
+	alreadyAddedIds = new Set(),
+	placeholder = m.journey_add_document(),
+	onSelect
+}: Props = $props();
+
+const listboxId = 'doc-picker-listbox';
+
+const picker = createTypeahead<DocumentOption>({
+	fetchUrl: (q) =>
+		fetch(`/api/documents/search?q=${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
+				}))
+			)
+});
+
+let inputValue = $state('');
+
+function handleInput(e: Event) {
+	const q = (e.currentTarget as HTMLInputElement).value;
+	inputValue = q;
+	if (q.trim().length >= 1) {
+		picker.setQuery(q);
+	} else {
+		picker.close();
+	}
+}
+
+function handleSelect(doc: DocumentOption) {
+	if (alreadyAddedIds.has(doc.id!)) return;
+	inputValue = '';
+	picker.close();
+	onSelect(doc);
+}
+
+function formatDocLabel(doc: DocumentOption): string {
+	if (!doc.documentDate) return doc.title;
+	const label = formatDocumentDate(
+		doc.documentDate,
+		doc.metaDatePrecision as DatePrecision,
+		doc.metaDateEnd,
+		null,
+		getLocale()
+	);
+	return `${doc.title} · ${label}`;
+}
+</script>
+
+<div use:clickOutside onclickoutside={() => picker.close()} class="relative">
+	<input
+		type="text"
+		role="combobox"
+		autocomplete="off"
+		aria-expanded={picker.isOpen && picker.results.length > 0}
+		aria-controls={listboxId}
+		aria-autocomplete="list"
+		placeholder={placeholder}
+		value={inputValue}
+		oninput={handleInput}
+		class="block w-full rounded border border-line bg-surface px-3 py-2 text-sm text-ink placeholder:text-ink-3 focus:outline-none focus-visible:ring-2 focus-visible:ring-focus-ring"
+	/>
+
+	{#if picker.isOpen && (picker.results.length > 0 || picker.loading)}
+		<ul
+			id={listboxId}
+			role="listbox"
+			class="ring-opacity-5 absolute z-50 mt-1 max-h-60 w-full overflow-auto rounded-md bg-surface py-1 text-sm shadow-lg ring-1 ring-black"
+		>
+			{#if picker.loading}
+				<li class="px-3 py-2 text-ink-2">{m.comp_multiselect_loading()}</li>
+			{:else}
+				{#each picker.results as doc (doc.id)}
+					{@const disabled = alreadyAddedIds.has(doc.id!)}
+					<li
+						role="option"
+						aria-selected={false}
+						aria-disabled={disabled}
+						onclick={() => handleSelect(doc)}
+						onkeydown={(e) => e.key === 'Enter' && handleSelect(doc)}
+						tabindex={disabled ? -1 : 0}
+						class={[
+							'px-3 py-2 text-ink select-none',
+							disabled
+								? 'cursor-default opacity-50'
+								: 'cursor-pointer hover:bg-muted focus:bg-muted focus:outline-none'
+						].join(' ')}
+					>
+						{formatDocLabel(doc)}
+						{#if disabled}
+							<span class="sr-only">{m.journey_already_added()}</span>
+						{/if}
+					</li>
+				{/each}
+			{/if}
+		</ul>
+	{/if}
+</div>

frontend/src/lib/document/DocumentPickerDropdown.svelte.spec.ts

@@ -0,0 +1,92 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import { page, userEvent } from 'vitest/browser';
+import DocumentPickerDropdown from './DocumentPickerDropdown.svelte';
+
+const waitForDebounce = () => new Promise((r) => setTimeout(r, 350));
+
+const docFactory = (id: string, title: string) => ({
+	id,
+	title,
+	documentDate: '1880-01-01',
+	metaDatePrecision: 'DAY' as const,
+	metaDateEnd: undefined
+});
+
+function mockSearchResponse(items: ReturnType<typeof docFactory>[]) {
+	vi.stubGlobal(
+		'fetch',
+		vi.fn().mockResolvedValue({
+			ok: true,
+			json: vi.fn().mockResolvedValue({ items })
+		})
+	);
+}
+
+afterEach(() => {
+	cleanup();
+	vi.unstubAllGlobals();
+});
+
+describe('DocumentPickerDropdown — empty query guard', () => {
+	it('does not call fetch on empty query', async () => {
+		const fetchMock = vi.fn();
+		vi.stubGlobal('fetch', fetchMock);
+
+		render(DocumentPickerDropdown, { onSelect: vi.fn() });
+		await userEvent.fill(page.getByRole('combobox'), '');
+		await waitForDebounce();
+
+		expect(fetchMock).not.toHaveBeenCalled();
+	});
+});
+
+describe('DocumentPickerDropdown — already-added indicator', () => {
+	it('shows already-added document as aria-disabled with sr-only hint', async () => {
+		mockSearchResponse([docFactory('d1', 'Brief von Eugenie'), docFactory('d2', 'Brief 2')]);
+
+		render(DocumentPickerDropdown, {
+			alreadyAddedIds: new Set(['d1']),
+			onSelect: vi.fn()
+		});
+
+		await userEvent.fill(page.getByRole('combobox'), 'Brief');
+		await waitForDebounce();
+
+		const disabledOption = page.getByRole('option', { name: /Brief von Eugenie/i });
+		await expect.element(disabledOption).toHaveAttribute('aria-disabled', 'true');
+		// Screen-reader text "bereits enthalten" must be present in the option
+		await expect.element(page.getByText(/bereits enthalten/i)).toBeInTheDocument();
+	});
+});
+
+describe('DocumentPickerDropdown — selection', () => {
+	it('calls onSelect with the item when a non-disabled option is clicked', async () => {
+		const onSelect = vi.fn();
+		mockSearchResponse([docFactory('d1', 'Brief von Eugenie')]);
+
+		render(DocumentPickerDropdown, { onSelect });
+
+		await userEvent.fill(page.getByRole('combobox'), 'Brief');
+		await waitForDebounce();
+		await userEvent.click(page.getByRole('option', { name: /Brief von Eugenie/i }));
+
+		expect(onSelect).toHaveBeenCalledWith(expect.objectContaining({ id: 'd1' }));
+	});
+
+	it('does not call onSelect when an aria-disabled option is clicked', async () => {
+		const onSelect = vi.fn();
+		mockSearchResponse([docFactory('d1', 'Brief von Eugenie')]);
+
+		render(DocumentPickerDropdown, {
+			alreadyAddedIds: new Set(['d1']),
+			onSelect
+		});
+
+		await userEvent.fill(page.getByRole('combobox'), 'Brief');
+		await waitForDebounce();
+		await userEvent.click(page.getByRole('option', { name: /Brief von Eugenie/i }));
+
+		expect(onSelect).not.toHaveBeenCalled();
+	});
+});