Add integration test assertions for stepCompleted with next field

Add didFireStepCompleted helper to the base OnboardingPage test page
object and verify in both v3 and v4 full-flow tests that each step
transition fires stepCompleted with the correct id and next fields.

https://claude.ai/code/session_01JnUmv2xkXxdF12a3EDyVXR

Author: claude

special-pages/pages/onboarding/integration-tests/onboarding.page.js

@@ -294,6 +294,24 @@ export class OnboardingPage {
         ]);
     }
 
+    /**
+     * Asserts that stepCompleted notifications were fired with the expected id and next fields.
+     * @param {{ id: string, next: string | null }[]} expectedSteps
+     */
+    async didFireStepCompleted(expectedSteps) {
+        const calls = await this.mocks.outgoing({ names: ['stepCompleted'] });
+        expect(calls).toMatchObject(
+            expectedSteps.map(({ id, next }) => ({
+                payload: {
+                    context: 'specialPages',
+                    featureName: 'onboarding',
+                    method: 'stepCompleted',
+                    params: { id, next },
+                },
+            })),
+        );
+    }
+
     async keepInTaskbar() {
         const { page } = this;
         const locator = this.build.switch({

special-pages/pages/onboarding/integration-tests/onboarding.v3.spec.js

@@ -206,6 +206,17 @@ test.describe('onboarding v3', () => {
         await page.getByRole('button', { name: 'Search & Duck.ai' }).click();
         await page.getByRole('button', { name: 'Search Only' }).click();
         await onboarding.startBrowsing();
+
+        // Verify stepCompleted was fired for each step with the correct next field
+        await onboarding.didFireStepCompleted([
+            { id: 'welcome', next: 'getStarted' },
+            { id: 'getStarted', next: 'makeDefaultSingle' },
+            { id: 'makeDefaultSingle', next: 'systemSettings' },
+            { id: 'systemSettings', next: 'duckPlayerSingle' },
+            { id: 'duckPlayerSingle', next: 'customize' },
+            { id: 'customize', next: 'addressBarMode' },
+            { id: 'addressBarMode', next: null },
+        ]);
     });
 
     test('shows v3 flow without system settings step', async ({ page }, workerInfo) => {

special-pages/pages/onboarding/integration-tests/onboarding.v4.spec.js

@@ -204,6 +204,17 @@ test.describe('onboarding v4', () => {
         await page.getByRole('button', { name: 'Search & Duck.ai' }).click();
         await page.getByRole('button', { name: 'Search Only' }).click();
         await onboarding.startBrowsing();
+
+        // Verify stepCompleted was fired for each step with the correct next field
+        await onboarding.didFireStepCompleted([
+            { id: 'welcome', next: 'getStarted' },
+            { id: 'getStarted', next: 'makeDefaultSingle' },
+            { id: 'makeDefaultSingle', next: 'systemSettings' },
+            { id: 'systemSettings', next: 'duckPlayerSingle' },
+            { id: 'duckPlayerSingle', next: 'customize' },
+            { id: 'customize', next: 'addressBarMode' },
+            { id: 'addressBarMode', next: null },
+        ]);
     });
 
     test.describe('Given I am on the settings step with dock-instructions variant', () => {