test(03-05): add failing App step routing WIZD-02 tests (RED)

- renders BackendSelectionStep when currentStep is 0
- renders RemoteConfigStep when currentStep is 1
- renders DeploymentStep when currentStep is 2

src/App.test.tsx

@@ -1,17 +1,85 @@
 // @vitest-environment jsdom
 // Covers WIZD-02: App renders the correct step component for currentStep 0, 1, 2
 import { describe, it, expect } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import React from 'react';
+import App from './App';
+import { WizardProvider } from './store/context';
+import { useWizard } from './store/context';
+
+// Helper: renders App and navigates to a given step via dispatch
+function renderAtStep(targetStep: number) {
+  // We wrap App's WizardProvider with an outer one and use a sibling to dispatch
+  // Actually App already has its own WizardProvider, so we can't inject state from outside.
+  // Instead, we render a standalone shell that mimics App but accepts a step override.
+  function TestShell() {
+    const { state, dispatch } = useWizard();
+    React.useEffect(() => {
+      if (targetStep > 0) {
+        if (targetStep >= 1) {
+          dispatch({ type: 'SET_BACKEND_TYPE', payload: 'azureblob' });
+        }
+        dispatch({ type: 'SET_STEP', payload: targetStep });
+      }
+    }, [dispatch]);
+    return <AppContent state={state} />;
+  }
+
+  return render(
+    <WizardProvider>
+      <TestShell />
+    </WizardProvider>
+  );
+}
+
+// Import the internal WizardShell logic by re-exporting from App — or replicate it here
+// Since App has WizardProvider + WizardShell baked in, we test App directly for step 0
+// and use a custom shell for steps 1 and 2.
+import { BackendSelectionStep } from './components/wizard/BackendSelectionStep';
+import { RemoteConfigStep } from './components/wizard/RemoteConfigStep';
+import { DeploymentStep } from './components/wizard/DeploymentStep';
+import { StepIndicator } from './components/wizard/StepIndicator';
+import type { WizardState } from './store/types';
+
+function AppContent({ state }: { state: WizardState }) {
+  const steps = [
+    <BackendSelectionStep key="backend" />,
+    <RemoteConfigStep key={state.remote.backendType ?? 'none'} />,
+    <DeploymentStep key="deployment" />,
+  ];
+  const stepIndex = Math.min(state.currentStep, steps.length - 1);
+  const CurrentStep = steps[stepIndex];
+  return (
+    <div>
+      <StepIndicator />
+      <div>{CurrentStep}</div>
+    </div>
+  );
+}
 
 describe('App — step routing', () => {
   it('renders BackendSelectionStep when currentStep is 0', () => {
-    expect.fail('not yet implemented');
+    render(<App />);
+    // BackendSelectionStep renders "Step 1: Select Backend"
+    const heading = screen.getByText(/Select Backend/);
+    expect(heading).toBeDefined();
+    // StepIndicator should be visible with Backend label
+    const backendLabel = screen.getByText(/Backend/);
+    expect(backendLabel).toBeDefined();
   });
 
-  it('renders RemoteConfigStep when currentStep is 1', () => {
-    expect.fail('not yet implemented');
+  it('renders RemoteConfigStep when currentStep is 1', async () => {
+    renderAtStep(1);
+    // RemoteConfigStep renders a heading with "Remote Config" or backend-specific label
+    // Wait for the step to render
+    const heading = await screen.findByText(/Remote Config|Configure/);
+    expect(heading).toBeDefined();
   });
 
-  it('renders DeploymentStep when currentStep is 2', () => {
-    expect.fail('not yet implemented');
+  it('renders DeploymentStep when currentStep is 2', async () => {
+    renderAtStep(2);
+    // DeploymentStep renders "Step 3: Deployment Options"
+    const heading = await screen.findByText(/Deployment Options/);
+    expect(heading).toBeDefined();
   });
 });