test(magazine): cover driving seek controls

PROJECT_MAP.md

@@ -52,7 +52,7 @@ Two self-hosted Docker instances, both port 7890:
 | Studio (phase wizard) | — | `studio.js` | mature |
 | TTS engines / routing | `routes/tts.py`, `core/routing.py` | `engines.js` | mature |
 | STT | `routes/stt.py` | — | mature |
-| **Magazines** | `core/magazine.py`, `routes/magazine.py` | `magazine.js`, `s-magazine.html` | **P0 + P1** |
+| **Magazines** | `core/magazine.py`, `routes/magazine.py` | `magazine.js`, `s-magazine.html` | **P0 + P1**; generated-MP3 playlist and driving-mode seek/±15 s transport |
 
 ## Data model
 

architecture/magazine-ingestion.md

@@ -258,9 +258,12 @@ works regardless.
 
 `#mag-driving` is a full-screen overlay, not a separate playback path: it
 reuses whatever is already playing or queued, so entering it never
-interrupts an article in progress. Two oversized controls (skip, play/pause)
-and no other interactive surface, matching the "no interaction required"
-behaviour the manual originally specified as a P2 goal.
+interrupts an article in progress. Its touch-sized transport exposes the
+previous/next article, back/forward 15 seconds, play/pause, and direct seeking
+on the shared playlist `<audio>` element. Seeking is bounded to the current
+track. Playback speed and the optional synchronized text/image companion are
+browser-local preferences; none of these controls changes server-side article
+data or creates a second playback state.
 
 ### Automatic sidebar/advert exclusion
 

tests/magazine.spec.js

@@ -217,6 +217,46 @@ test.describe('Magazine reader', () => {
     await expect(exportPicker.locator('.vp-item[data-value="smoke_voice"]')).toBeVisible();
   });
 
+  test('driving mode seeks and skips 15 seconds within the current article', async ({ page }) => {
+    await mockBackend(page, { articleStatus: 'approved', hasAudio: true });
+    await page.goto('/', { waitUntil: 'domcontentloaded' });
+    await page.waitForSelector('#app-skeleton', { state: 'detached', timeout: 15_000 });
+    await navTo(page, 's-magazine');
+    await page.locator('#mag-library-list .mag-card').first().click();
+    await page.locator('#mag-driving-open').click();
+    await expect(page.locator('#mag-driving')).toBeVisible();
+
+    // Use a deterministic two-minute track so the transport controls can be
+    // exercised without depending on the browser's media decoder clock.
+    await page.locator('#mag-playlist-audio').evaluate((audio) => {
+      audio.pause();
+      Object.defineProperties(audio, {
+        duration: { configurable: true, value: 120 },
+        currentTime: { configurable: true, writable: true, value: 60 },
+      });
+    });
+    const currentTime = () => page.locator('#mag-playlist-audio').evaluate((audio) => audio.currentTime);
+
+    await page.getByRole('button', { name: 'Back 15 seconds', exact: true }).click();
+    await expect.poll(currentTime).toBe(45);
+    await page.getByRole('button', { name: 'Forward 15 seconds', exact: true }).click();
+    await expect.poll(currentTime).toBe(60);
+
+    await page.locator('#mag-playlist-audio').evaluate((audio) => { audio.currentTime = 5; });
+    await page.getByRole('button', { name: 'Back 15 seconds', exact: true }).click();
+    await expect.poll(currentTime).toBe(0);
+    await page.locator('#mag-playlist-audio').evaluate((audio) => { audio.currentTime = 115; });
+    await page.getByRole('button', { name: 'Forward 15 seconds', exact: true }).click();
+    await expect.poll(currentTime).toBe(120);
+
+    const seek = page.getByRole('slider', { name: 'Position in article' });
+    await seek.evaluate((input) => {
+      input.value = '250';
+      input.dispatchEvent(new Event('input', { bubbles: true }));
+    });
+    await expect.poll(currentTime).toBe(30);
+  });
+
   test('library lists a magazine and opens its contents tree', async ({ page }) => {
     await mockBackend(page);
     await page.goto('/', { waitUntil: 'domcontentloaded' });