feat(analytics): add behavior and payment funnel tracking

src/router/__tests__/navigation-resolver.test.ts

@@ -33,6 +33,27 @@ describe("navigation resolver", () => {
     ).toBe("/subscription?type=topup");
   });
 
+  it("preserves payment analytics context through auth redirects", () => {
+    const subscriptionUrl = ROUTE_BUILDERS.subscription("topup", {
+      payChannel: "stripe",
+      returnTo: "chat",
+      analytics: {
+        entryPoint: "chat_unlock",
+        triggerReason: "ad_landing",
+      },
+    });
+
+    expect(subscriptionUrl).toBe(
+      "/subscription?type=topup&payChannel=stripe&returnTo=chat&analytics_entry=chat_unlock&analytics_reason=ad_landing",
+    );
+    expect(
+      resolveAuthenticatedNavigation({
+        loginStatus: "guest",
+        targetUrl: subscriptionUrl,
+      }),
+    ).toBe(ROUTE_BUILDERS.authWithRedirect(subscriptionUrl));
+  });
+
   it("allows not logged in users to enter chat for guest bootstrap", () => {
     expect(
       resolveRouteGuardRedirect({