fix: close browser session lifecycle gaps

apps/web/tests/app-shell.test.tsx

@@ -1,7 +1,7 @@
 import { render, screen } from "@testing-library/react";
 import "@testing-library/jest-dom/vitest";
 import userEvent from "@testing-library/user-event";
-import { describe, expect, it, vi } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import { App } from "../src/App.js";
 import { createInitialHarnessState, type HarnessClientState } from "../src/store/reducer.js";
 
@@ -24,6 +24,7 @@ function makeStore() {
     subscribe: () => () => undefined,
     sendMessage,
     cancel: vi.fn().mockResolvedValue({ cancelled: false }),
+    dispose: vi.fn().mockResolvedValue(undefined),
     start: vi.fn().mockResolvedValue(undefined),
     getModelConfig: vi.fn().mockResolvedValue({
       modelConfig: { configured: true, source: "environment", providerId: "openai", api: "openai-responses", modelId: "gpt-test", supportsImages: true },
@@ -31,6 +32,8 @@ function makeStore() {
   };
 }
 
+afterEach(() => vi.unstubAllGlobals());
+
 describe("App", () => {
   it("renders the three primary work areas", () => {
     render(<App store={makeStore()} autoStart={false} modelConfigured />);
@@ -55,4 +58,37 @@ describe("App", () => {
     expect(screen.getByRole("button", { name: "发送消息" })).toBeDisabled();
     expect(screen.getByText("请先配置模型连接")).toBeVisible();
   });
+
+  it("switches to the event timeline in the mobile tab layout", async () => {
+    vi.stubGlobal("matchMedia", vi.fn(() => ({
+      matches: true,
+      media: "(max-width: 720px)",
+      onchange: null,
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+      addListener: vi.fn(),
+      removeListener: vi.fn(),
+      dispatchEvent: vi.fn(),
+    })));
+    const user = userEvent.setup();
+    render(<App store={makeStore()} autoStart={false} modelConfigured />);
+
+    await user.click(screen.getByRole("tab", { name: "Events" }));
+
+    expect(screen.getByRole("tab", { name: "Events" })).toHaveAttribute("aria-selected", "true");
+    expect(screen.getByRole("region", { name: "Event Timeline" })).toBeVisible();
+    expect(screen.queryByRole("main", { name: "Streaming Chat" })).not.toBeInTheDocument();
+  });
+
+  it("deletes the old session before starting a reset session", async () => {
+    const user = userEvent.setup();
+    const store = makeStore();
+    render(<App store={store} autoStart={false} modelConfigured />);
+
+    await user.click(screen.getByRole("button", { name: "重置训练会话" }));
+
+    expect(store.dispose).toHaveBeenCalledTimes(1);
+    expect(store.start).toHaveBeenCalledTimes(1);
+    expect(store.dispose.mock.invocationCallOrder[0]).toBeLessThan(store.start.mock.invocationCallOrder[0] ?? 0);
+  });
 });