test(vocabulary): reload with the tag window at its top; one arrival appends one page (#530)

Firefox restores a scrolled window on reload, and its end then appends a page before the check.

tests/browser/workspace-layout-tags-system.spec.mjs

@@ -120,6 +120,10 @@ test('a long tag list scrolls in its own window and the page does not grow (D183
     await tagWindow(page).evaluate(node=>{node.scrollTop=node.scrollHeight;});
     await expect(rows(page)).toHaveCount(200);
     expect(await page.evaluate(()=>window.scrollY)).toBe(0);
+    // One arrival is one page: the appended rows push the end away, so pages do not chain while more remain.
+    await nextFrame(page);await nextFrame(page);
+    await expect(rows(page)).toHaveCount(200);
+    await expect(loadMore(page)).toBeVisible();
 
     // Load more works from below the window, with the window not at its end.
     await tagWindow(page).evaluate(node=>{node.scrollTop=0;});await nextFrame(page);

tests/browser/workspace-vocabulary.spec.mjs

@@ -145,6 +145,8 @@ test('long vocabularies append and Load more is keyboard reachable',async({page,
     await expect(loadMore(page)).toHaveCount(0);
     await expect(rows(page).nth(200).getByRole('button',{name:'Browse',exact:true})).toBeFocused();
     await expect(rows(page).locator('td:nth-child(1)')).toHaveText(manifest.tags);
+    // Reload with the window at its top: Firefox restores a scrolled window, whose end then appends a page before the check.
+    await main(page).locator('.two-col .table-wrap').evaluate(node=>new Promise(resolve=>{node.scrollTop=0;requestAnimationFrame(()=>requestAnimationFrame(resolve));}));
     await page.reload();
     await expect(rows(page)).toHaveCount(100);
     // D183: the end of the list arrives inside the tag window.