Complete Greatest covers and use Japanese navigation label

tools/test-greatest-ui.js

@@ -42,6 +42,7 @@ async function freePort() {
     page.on('pageerror', error => errors.push(error.message));
     await page.goto(base + '/greatest.html');
     await page.getByRole('heading', { name: 'Shijō Saikō no Manga' }).waitFor();
+    assert.equal(await page.getByRole('link', { name: 'Shijō Saikō no Manga' }).textContent(), 'Shijō Saikō no Manga');
     assert.equal(await page.locator('.greatest-period').count(), 13);
     assert.equal(await page.locator('.greatest-tile').count(), 106);
     const astro = page.locator('.greatest-tile').filter({ hasText: 'Astro Boy' });
@@ -54,6 +55,7 @@ async function freePort() {
     await page.getByRole('dialog').getByText('Community votes: 🔥 1').waitFor();
     await page.getByRole('dialog').getByRole('button', { name: 'Close' }).click();
     await page.setViewportSize({ width: 390, height: 844 });
+    assert.equal(await page.locator('.nav-greatest').evaluate(el => getComputedStyle(el, '::after').content), '"Saikō"');
     assert.ok(await page.evaluate(() => document.documentElement.scrollWidth <= innerWidth), 'Mobile horizontal overflow');
     await page.getByRole('button', { name: '📚 In library' }).click();
     assert.equal(await page.locator('.greatest-tile').count(), 0);