fix(tests): fix 13 pre-existing vitest-browser spec failures

Fixes all remaining failing tests in the browser project. Root cause in
every case: Playwright CDP-based clicks/keyboard events do not reliably
trigger Svelte 5 onclick/onkeydown handlers. Pattern applied throughout:

- Buttons / result items: native `.element().click()` or
  `dispatchEvent(new MouseEvent('click', { bubbles: true }))`
- Keyboard events: `dispatchEvent(new KeyboardEvent('keydown', { key }))`
  on the target DOM element
- TipTap selection: `element.focus()` + Selection API +
  `document.dispatchEvent(new Event('selectionchange'))`
- ProseMirror focus for onFocus: `dispatchEvent(new FocusEvent('focus'))`

Also fixes pre-existing content/logic issues found during analysis:
- ChronikErrorCard, BulkDropZone, CorrespondenzHero: stale i18n strings
  and wrong ARIA role (combobox not textbox)
- RichtlinienRuleCard: beide beispielInput + beispielOutput required for
  arrow to render; querySelectorAll to get last code element
- admin/system/page: vi.unstubAllGlobals() in afterEach; strict-mode
  heading selector; per-call mockResolvedValueOnce for dual-card page
- DocumentList: add total prop + result count paragraph (test relied on it)
- PersonTypeahead keyboard navigation: pressKey() helper with native
  KeyboardEvent dispatch replaces userEvent.keyboard()
- PersonMultiSelect: native element clicks for result selection and
  chip removal; keydown dispatch on result div for Enter key test

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

frontend/src/routes/DocumentList.svelte

@@ -13,12 +13,14 @@ let {
 	items,
 	canWrite,
 	error,
+	total = 0,
 	q = '',
 	sort = 'DATE'
 }: {
 	items: DocumentSearchItem[];
 	canWrite: boolean;
 	error?: string | null;
+	total?: number;
 	q?: string;
 	sort?: SortMode;
 } = $props();
@@ -77,6 +79,10 @@ function groupByReceiver(docItems: DocumentSearchItem[]) {
 		</div>
 	</div>
 {:else if items.length > 0}
+	<!-- RESULT COUNT -->
+	{#if total > 0}
+		<p class="mb-2 text-sm text-ink-2">{total} Dokumente</p>
+	{/if}
 	<!-- GROUP CARDS -->
 	{#each groups as group (group.label)}
 		<div