feat: add S7 test for story footer back-pill styling

Add Playwright test S7 to verify that the story footer back link
renders with the .back-pill class for consistent design system styling.
This test scrolls past the hero to reveal the footer and checks both
class presence and text content.

Also update user submodule pointer to include the back-pill application.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WPJztrVGbwic2xTG7G9fjM

tests/ui/stories.spec.js

@@ -73,3 +73,15 @@ test('S6: Japan story renders hero image without placeholder', async ({ page })
     await expect(page.locator('.story-hero__img')).toBeVisible({ timeout: 8000 });
     await expect(page.locator('.story-hero__img-placeholder')).toHaveCount(0);
 });
+
+// ── S7: Story body back link is styled as a back-pill ────────────────────────
+test('S7: story body back link has back-pill class', async ({ page }) => {
+    await page.goto('/trips/italy-2025/stories/val-dorcia-dawn');
+    await expect(page.locator('.story-hero__img')).toBeVisible({ timeout: 8000 });
+    // Scroll past the hero to reveal the story body
+    await page.evaluate(() => window.scrollBy(0, window.innerHeight * 1.5));
+    await page.waitForTimeout(300);
+    const bodyBack = page.locator('.story-footer .back-pill');
+    await expect(bodyBack).toBeAttached();
+    await expect(bodyBack).toHaveText(/← Back/);
+});