fix: keep replay cancellation honest

web/apps/console/src/demo/agent/timelineAgent.test.tsx

@@ -89,4 +89,25 @@ describe("useTimelineAgent", () => {
     const { result } = renderHook(() => useTimelineAgent(demo, "live"));
     expect(result.current.canRun).toBe(false);
   });
+
+  it("does not advance replay cancellation into the submitted recording branch", async () => {
+    const cancelReview = vi.fn(async () => {});
+    const next = vi.fn(async () => {});
+    const demo = demoController({
+      state: { ...initialDemoTimelineState, mode: "replay", phase: "review" },
+      cancelReview,
+      next,
+    });
+
+    const { result } = renderHook(() => useTimelineAgent(demo, "replay"));
+    await act(async () => result.current.cancelReview());
+
+    expect(cancelReview).toHaveBeenCalledWith("Cancelled by operator.");
+    expect(next).not.toHaveBeenCalled();
+    expect(result.current.messages.at(-1)?.parts).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ type: "tool-result" }),
+      ]),
+    );
+  });
 });

web/apps/console/src/demo/agent/timelineAgent.ts

@@ -88,7 +88,11 @@ export const useTimelineAgent = (
 
   const cancelReview = useCallback(async () => {
     await demo.cancelReview("Cancelled by operator.");
-    await demo.next();
+    // In replay the canonical recording only contains the submitted branch.
+    // Do not call next() or the UI would falsely advance into submitted evidence.
+    if (demo.state.mode === "live") {
+      await demo.next();
+    }
     setMessages((current) => appendToolMessage(
       current,
       "timeline-agent-cancel",