test(viewer): verify delete button click does not bubble to onclick

Documents the stopPropagation guarantee: clicking the trash button must
not trigger the annotation's onclick (which opens the block detail panel)
while the delete confirm is in progress.

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

frontend/src/lib/components/AnnotationShape.svelte.spec.ts

@@ -113,6 +113,28 @@ describe('AnnotationShape', () => {
 		expect(onDeleteRequest).toHaveBeenCalledOnce();
 	});
 
+	it('does not call onclick when delete button is clicked', async () => {
+		const onclick = vi.fn();
+		const onDeleteRequest = vi.fn();
+
+		render(AnnotationShape, {
+			annotation: makeAnnotation(),
+			isHovered: true,
+			isActive: false,
+			showDelete: true,
+			onDeleteRequest,
+			onclick,
+			onpointerenter: () => {},
+			onpointerleave: () => {}
+		});
+
+		const deleteBtn = page.getByTestId('annotation-delete-ann-1');
+		await deleteBtn.click();
+
+		expect(onclick).not.toHaveBeenCalled();
+		expect(onDeleteRequest).toHaveBeenCalledOnce();
+	});
+
 	it('calls onDeleteRequest when Delete key is pressed on the annotation', async () => {
 		const onDeleteRequest = vi.fn();