test(ads): lock the hint-pushed ad restarting the vs_ai gap (no over-serving)

ui/src/lib/ads.test.ts

@@ -108,6 +108,20 @@ describe('maybeShowInterstitial (client-mirrored gate)', () => {
     expect(mocks.vkShowInterstitial).toHaveBeenCalledTimes(1); // only the hint ad fired
   });
 
+  it('a hint-pushed ad restarts the vs_ai gap, so the next plain move is not over-served', async () => {
+    // The scenario the owner flagged: a vs_ai ad, then 20 min later a hinted move pushes an ad on
+    // its short gap, then a plain move 10 min after that must NOT fire — the shared timer restarted
+    // the 30-min vs_ai gap at the hint ad, so 10 min is not enough (it fires only 30 min after it).
+    const vsAi = { vsAi: true, online: true };
+    expect(await maybeShowInterstitial(ADS, 'move', vsAi)).toBe(true); // t0
+    vi.setSystemTime(BASE + 20 * 60_000); // +20 min: a hint pushes an ad on its 1-min gap
+    expect(await maybeShowInterstitial(ADS, 'hint', vsAi)).toBe(true);
+    vi.setSystemTime(BASE + 30 * 60_000); // +10 min after the hint ad
+    expect(await maybeShowInterstitial(ADS, 'move', vsAi)).toBe(false);
+    vi.setSystemTime(BASE + 50 * 60_000); // +30 min after the hint ad
+    expect(await maybeShowInterstitial(ADS, 'move', vsAi)).toBe(true);
+  });
+
   it('uses the longer vs_ai cooldown for a vs_ai move', async () => {
     expect(await maybeShowInterstitial(ADS, 'move', { vsAi: true, online: true })).toBe(true);
     vi.setSystemTime(BASE + 1_799_000); // +1799s < the 1800s vs_ai cooldown