Open Sync more for an MCP preset at choosing what to sync

The launcher passed only reconnect through for MCP presets, so Sync more
on a Linear account asked to sign in again instead of showing its teams.

frontend/src/connectors/useConnectorLauncher.test.tsx

@@ -0,0 +1,92 @@
+import { configureStore } from '@reduxjs/toolkit';
+import { act } from 'react';
+import { createRoot, type Root } from 'react-dom/client';
+import { Provider } from 'react-redux';
+import { MemoryRouter } from 'react-router-dom';
+
+// The wizard is tested on its own; here only what it is opened with matters.
+vi.mock('./ConnectWizard', () => ({
+  default: ({
+    mode,
+    connectionId,
+  }: {
+    mode: string;
+    connectionId?: string;
+  }) => <div data-testid="wizard">{`${mode}:${connectionId ?? ''}`}</div>,
+}));
+vi.mock('../modals/MCPServerModal', () => ({ default: () => null }));
+
+import connectorsReducer from './connectorsSlice';
+import type { ConnectorDefinition } from './types';
+import useConnectorLauncher, {
+  type LaunchOptions,
+} from './useConnectorLauncher';
+
+Object.assign(globalThis, { IS_REACT_ACT_ENVIRONMENT: true });
+
+const LINEAR = {
+  key: 'mcp:linear',
+  name: 'Linear',
+  auth_kind: 'mcp_oauth',
+  mcp_url: 'https://mcp.linear.app/mcp',
+  sync_ingestor: 'linear',
+} as unknown as ConnectorDefinition;
+
+let launchRef: ((c: ConnectorDefinition, o?: LaunchOptions) => void) | null =
+  null;
+
+function Harness() {
+  const { launch, modals } = useConnectorLauncher();
+  launchRef = launch;
+  return <>{modals}</>;
+}
+
+describe('useConnectorLauncher', () => {
+  let container: HTMLDivElement;
+  let root: Root;
+
+  beforeEach(async () => {
+    container = document.createElement('div');
+    document.body.appendChild(container);
+    root = createRoot(container);
+    const store = configureStore({
+      reducer: {
+        connectors: connectorsReducer,
+        preference: (state = { token: null }) => state,
+      },
+    });
+    await act(async () => {
+      root.render(
+        <Provider store={store}>
+          <MemoryRouter>
+            <Harness />
+          </MemoryRouter>
+        </Provider>,
+      );
+    });
+  });
+
+  afterEach(async () => {
+    await act(async () => root.unmount());
+    container.remove();
+  });
+
+  const wizard = () =>
+    container.querySelector('[data-testid="wizard"]')?.textContent;
+
+  it('opens an MCP preset that syncs straight at picking what to sync', async () => {
+    await act(async () =>
+      launchRef!(LINEAR, { mode: 'sync', connectionId: 'c1' }),
+    );
+    expect(wizard()).toBe('sync:c1');
+  });
+
+  it('opens an MCP preset at signing in to connect or reconnect', async () => {
+    await act(async () => launchRef!(LINEAR));
+    expect(wizard()).toBe('connect:');
+    await act(async () =>
+      launchRef!(LINEAR, { mode: 'reconnect', connectionId: 'c1' }),
+    );
+    expect(wizard()).toBe('reconnect:c1');
+  });
+});

frontend/src/connectors/useConnectorLauncher.tsx

@@ -62,7 +62,8 @@ export default function useConnectorLauncher({
         setActive({
           kind: 'wizard',
           connector,
-          mode: options.mode === 'reconnect' ? 'reconnect' : 'connect',
+          // Sync more from an account skips signing in, like any connector.
+          mode: options.mode ?? 'connect',
           connectionId: options.connectionId,
           mcpToolId:
             typeof options.mcpServer?.id === 'string'