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/admin/entity-nav.svelte.spec.ts

@@ -76,7 +76,13 @@ describe('EntityNav — flyout', () => {
 		document.querySelector<HTMLButtonElement>('[data-flyout-trigger]')!.click();
 		await expect.element(page.getByRole('dialog')).toBeInTheDocument();
 		const dialog = document.querySelector('[role="dialog"]')!;
-		dialog.querySelector<HTMLAnchorElement>('a[href^="/admin/"]')!.click();
+		const link = dialog.querySelector<HTMLAnchorElement>('a[href^="/admin/"]')!;
+		// Prevent the browser from navigating the test iframe to /admin/... (which
+		// would redirect to /login and kill the iframe connection).  preventDefault()
+		// on the capture phase suppresses navigation while still letting the Svelte
+		// onclick handler (closeFlyout) run on the bubbling phase.
+		link.addEventListener('click', (e) => e.preventDefault(), { capture: true, once: true });
+		link.click();
 		await expect.element(page.getByRole('dialog')).not.toBeInTheDocument();
 	});
 });