test(transcription): cover 44px touch target on mention search input

For issue #380 NFR. The transcriber audience is 60+ on laptops/tablets;
the search input must meet WCAG 2.2 AA touch target dimensions just like
the existing person result rows.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/lib/shared/discussion/MentionDropdown.svelte.spec.ts

@@ -77,6 +77,18 @@ describe('MentionDropdown — search input', () => {
 		await expect.element(page.getByText(m.person_mention_search_prompt())).not.toBeInTheDocument();
 	});
 
+	it('search input wrapper meets the 44px touch target (WCAG 2.2 AA)', async () => {
+		render(MentionDropdown, {
+			model: makeModel(),
+			editorQuery: '',
+			onSearch: () => {}
+		});
+
+		const input = document.querySelector('[data-test-search-input]') as HTMLElement;
+		expect(input).not.toBeNull();
+		expect(input.className).toContain('min-h-[44px]');
+	});
+
 	it('invokes onSearch with the current value whenever the user types', async () => {
 		const onSearch = vi.fn();
 		render(MentionDropdown, {