fix : reaible vistor count

tests/security-redis.integration.test.ts

@@ -54,14 +54,33 @@ describeWithRedis("shared Redis security paths", () => {
   });
 
   it("tracks visitor counts without a separate Redis round trip per visitor", async () => {
-    const first = await updateVisitorPresence({ tabId: `${runId}:1`, guideId: "guide-a", active: true });
+    const first = await updateVisitorPresence({ tabId: `${runId}:1`, browserId: `${runId}:browser-1`, guideId: "guide-a", active: true });
     expect(first.global).toBe(1);
     expect(first.guide).toBe(1);
-    await updateVisitorPresence({ tabId: `${runId}:2`, guideId: "guide-a", active: true });
+    const second = await updateVisitorPresence({ tabId: `${runId}:2`, browserId: `${runId}:browser-2`, guideId: "guide-a", active: true });
+    expect(second.global).toBe(2);
+    expect(second.guide).toBe(2);
     const count = await publisher.zcard(`${process.env.REDIS_PRESENCE_PREFIX}:visitors`);
     expect(count).toBe(2);
   });
 
+  it("counts a browser once across tabs without losing either guide", async () => {
+    const browserId = `${runId}:browser-3`;
+    const firstTab = `${runId}:3`;
+    const secondTab = `${runId}:4`;
+    const firstGuide = await updateVisitorPresence({ tabId: firstTab, browserId, guideId: "guide-c", active: true });
+    const secondGuide = await updateVisitorPresence({ tabId: secondTab, browserId, guideId: "guide-d", active: true });
+    expect(secondGuide.global).toBe(firstGuide.global);
+    expect(secondGuide.guide).toBe(1);
+    expect(secondGuide.byGuide["guide-c"]).toBe(1);
+    const sameGuide = await updateVisitorPresence({ tabId: secondTab, browserId, guideId: "guide-c", active: true });
+    expect(sameGuide.guide).toBe(1);
+    expect(sameGuide.byGuide["guide-d"]).toBeUndefined();
+    const afterLeave = await updateVisitorPresence({ tabId: secondTab, browserId, guideId: "guide-d", active: false });
+    expect(afterLeave.byGuide["guide-c"]).toBe(1);
+    expect(afterLeave.byGuide["guide-d"]).toBeUndefined();
+  });
+
   it("fans one subscribed topic out to two SSE clients", async () => {
     const topic = `page:${runId}`;
     const first = new AbortController();