expect(header.querySelector(".nav-collapse-toggle")).not.toBeNull();

});

it("preserves the active session when opening chat from sidebar navigation", async () => {

it("preserves session navigation and keeps focus mode scoped to chat", async () => {

const app = mountApp("/sessions?session=agent:main:subagent:task-123");

await app.updateComplete;

expect(app.sessionKey).toBe("agent:main:subagent:task-123");

expect(window.location.pathname).toBe("/chat");

expect(window.location.search).toBe("?session=agent%3Amain%3Asubagent%3Atask-123");

});

it("keeps focus mode scoped to the chat tab", async () => {

const app = mountApp("/chat");

await app.updateComplete;

const shell = app.querySelector(".shell");

expect(shell).not.toBeNull();

await app.updateComplete;

expect(shell?.classList.contains("shell--chat-focus")).toBe(true);

const link = app.querySelector<HTMLAnchorElement>('a.nav-item[href="/channels"]');

expect(link).not.toBeNull();

link?.dispatchEvent(new MouseEvent("click", { bubbles: true, cancelable: true, button: 0 }));

const channelsLink = app.querySelector<HTMLAnchorElement>('a.nav-item[href="/channels"]');

expect(channelsLink).not.toBeNull();

channelsLink?.dispatchEvent(

new MouseEvent("click", { bubbles: true, cancelable: true, button: 0 }),

);

await app.updateComplete;

expect(app.tab).toBe("channels");