feat: poc integration tests for identities management express.js samples

[wassimoo]

This PoC introduces integration tests for Ory Identity session management flows, ensuring that the code examples in our documentation work correctly end-to-end.

The tests run against a test Express.js server that directly imports and uses code examples from the documentation.

While the tests use Ory's self-service API for login (via selfServiceLogin() utility), they validate the complete end-to-end flows for:

1. Logout Flow: After authenticating via self-service API, the tests verify that the logout endpoint in the example app correctly handles session termination and redirects appropriately.

2. Session Management Flow: Tests verify that authenticated sessions can be retrieved and validated through the example app's session endpoints.

Tests run in GitHub Actions with secrets injected for:

• ORY_SDK_URL - Ory test account endpoint URL
• TEST_USER_EMAIL - Test user credentials
• TEST_USER_PASSWORD - Test user credentials

Checklist

• [ ] I have read the contributing guidelines and signed the CLA.
• [ ] I have referenced an issue containing the design document if my change introduces a new feature.
• [ ] I have read the security policy.
• [ ] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got approval (please contact [email protected]) from the maintainers to push the changes.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [ ] I have added the necessary documentation within the code base (if appropriate).

Further comments