test: update onboarding tests to support v3 feature flag

[sean-brydon]

What does this PR do?

Updates the onboarding E2E tests to conditionally run either the V1 or V3 onboarding flow based on the onboarding-v3 feature flag status. This addresses the test failures in #26865 where enabling the onboarding-v3 feature flag globally causes the existing V1 tests to fail.

• Related to feat: enable onboarding-v3 feature flag #26865

Summary of Changes

• Renamed testOnboarding to testOnboardingV1 and added feature flag check to skip when V3 is enabled
• Added new testOnboardingV3 function that tests the new onboarding flow (plan selection → personal settings → calendar)
• V3 tests skip when the feature flag is disabled, V1 tests skip when enabled
• Both test suites run for GOOGLE, CAL, and SAML identity providers
• Cleaned up some inline comments in V1 tests

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. N/A - test changes only.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

1. Run the onboarding E2E tests with onboarding-v3 feature flag disabled - V1 tests should run, V3 tests should skip
2. Run the onboarding E2E tests with onboarding-v3 feature flag enabled - V3 tests should run, V1 tests should skip
3. Verify the V3 flow tests correctly navigate through: plan selection → personal settings → calendar → event-types

Human Review Checklist

• Verify the V3 test selectors (page.getByText("Personal"), page.getByLabel("Your name"), page.getByRole("button", { name: "Skip for now" })) match the actual UI elements - these were inferred from source code review
• Confirm the feature flag check using features.get("onboarding-v3") works correctly in CI environment
• Note: V3 onboarding components don't have data-testid attributes, so tests rely on text content/ARIA labels which may be more fragile

---

Link to Devin run: https://app.devin.ai/sessions/0bea3e60c75c498a8708733551122a52
Requested by: @sean-brydon

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR that start with 'DevinAI' or '@devin'.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring

[devin-ai-integration]

Devin is archived and cannot be woken up. Please unarchive Devin if you want to continue using it.