fix(web-shell): initialize workspace selector from ID

packages/web-shell/client/App.test.tsx

@@ -1848,6 +1848,37 @@ describe('App session callbacks', () => {
     );
   });
 
+  it('creates first sessions in the initial unlocked workspace', async () => {
+    mockConnection.sessionId = undefined;
+    mockWorkspace.capabilities = {
+      workspaces: [
+        { id: 'primary', cwd: '/workspace', primary: true, trusted: true },
+        {
+          id: 'secondary',
+          cwd: '/work/secondary',
+          primary: false,
+          trusted: true,
+        },
+      ],
+    } as typeof mockWorkspace.capabilities;
+    renderApp({ initialSelectedWorkspaceCwd: '/work/secondary' });
+    await flush();
+
+    expect(testState.latestChatEditorProps?.selectedWorkspaceCwd).toBe(
+      '/work/secondary',
+    );
+
+    await act(async () => {
+      testState.latestChatEditorProps?.onSubmit('secondary prompt');
+      await vi.waitFor(() => {
+        expect(mockSessionActions.createSession).toHaveBeenCalled();
+      });
+    });
+    expect(mockSessionActions.createSession).toHaveBeenCalledWith(
+      expect.objectContaining({ workspaceCwd: '/work/secondary' }),
+    );
+  });
+
   describe('worktree welcome toggle', () => {
     beforeEach(() => {
       mockConnection.sessionId = undefined;

packages/web-shell/client/App.tsx

@@ -656,6 +656,7 @@ export interface WebShellProps {
 }
 
 interface AppProps extends WebShellProps {
+  initialSelectedWorkspaceCwd?: string;
   lockedWorkspaceCwd?: string;
   lockedWorkspaceCapability?: DaemonWorkspaceCapability;
   restartSseOnPrompt?: boolean;
@@ -1112,6 +1113,7 @@ export function App({
   onSubmitBefore,
   restartSseOnPrompt,
   historyPageSize,
+  initialSelectedWorkspaceCwd,
   lockedWorkspaceCwd,
   lockedWorkspaceCapability,
 }: AppProps = {}) {
@@ -1392,7 +1394,7 @@ export function App({
   // so the ensureSessionForPrompt callback must read the latest value.
   const [selectedWorkspaceCwd, setSelectedWorkspaceCwd] = useState<
     string | undefined
-  >(undefined);
+  >(initialSelectedWorkspaceCwd);
   const selectedWorkspaceCwdRef = useRef(selectedWorkspaceCwd);
   selectedWorkspaceCwdRef.current = selectedWorkspaceCwd;
   const [selectedWorkspaceGitStatus, setSelectedWorkspaceGitStatus] = useState<

packages/web-shell/client/components/WorkspaceSessionProvider.tsx

@@ -243,6 +243,9 @@ export function WorkspaceSessionProvider({
         {...webShellProps}
         historyPageSize={historyPageSize}
         restartSseOnPrompt={restartSseOnPrompt}
+        initialSelectedWorkspaceCwd={
+          !lockWorkspaceCwd && targetWorkspace ? targetWorkspace.cwd : undefined
+        }
         lockedWorkspaceCwd={lockWorkspaceCwd ? targetWorkspace?.cwd : undefined}
         lockedWorkspaceCapability={
           lockWorkspaceCwd ? targetWorkspace : undefined

packages/web-shell/client/index.test.tsx

@@ -164,6 +164,25 @@ describe('WebShellWithProviders top-level boundary', () => {
     expect(appProps[0]?.lockedWorkspaceCwd).toBeUndefined();
   });
 
+  it('initializes an unlocked workspace selector from workspace id', () => {
+    workspaceCapabilities = {
+      workspaces: [
+        { id: 'primary', cwd: '/workspace', primary: true },
+        { id: 'secondary', cwd: '/work/secondary', primary: false },
+      ],
+    };
+
+    render(<WebShellWithProviders workspaceId="secondary" />);
+
+    expect(sessionProviderProps[0]).toMatchObject({
+      workspaceCwd: '/work/secondary',
+    });
+    expect(appProps[0]).toMatchObject({
+      initialSelectedWorkspaceCwd: '/work/secondary',
+    });
+    expect(appProps[0]?.lockedWorkspaceCwd).toBeUndefined();
+  });
+
   it('does not register an unknown unlocked workspace path', () => {
     const container = render(
       <WebShellWithProviders workspaceCwd="/work/missing" />,