test: use RFC 2606 reserved domains in fixtures and README example

[turegjorup]

Summary

Mirrors itk-dev/openid-connect-bundle#49: replaces invented domains in test fixtures and the README usage example with RFC 2606 reserved names — provider.example.org for IdP-side URLs (metadata, 28×) and app.example.org for application-side URLs (redirect URI, 2×).

Files Changed

• tests/Security/OpenIdConfigurationProviderTest.php - some.url → provider.example.org, redirect.url → app.example.org
• README.md - usage example redirectUri
• CHANGELOG.md - Unreleased bullet

Test Plan

• vendor/bin/phpunit — 103 tests, 192 assertions, green
• PHPStan max level + markdownlint — clean
• grep -rn 'some\.url|redirect\.url' tests/ src/ README.md — no matches

Notes

• https://logout.test already uses the RFC 2606-reserved .test TLD — left as is
• The azure_b2c_test.b2clogin.com fixture endpoints are a fake subdomain of Microsoft's real b2clogin.com — left as realistic Azure B2C shape examples (this library documents itself as made/tested for Azure AD B2C); happy to sweep those to provider.example.org too if preferred

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (d3b8c2b) to head (843d003).

Additional details and impacted files

@@             Coverage Diff             @@
##             develop       #53   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
  Complexity        71        71           
===========================================
  Files              1         1           
  Lines            185       185           
===========================================
  Hits             185       185           

Flag	Coverage Δ
unittests	100.00% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.