test: use RFC 2606 reserved domains in all test fixtures

[turegjorup]

Summary

Replaces every invented-but-registrable domain in the test fixtures with RFC 2606 reserved names, using subdomains for readability:

• provider.example.org — IdP-side URLs (metadata_url, authorization endpoint); a second provider in the multi-provider test uses other-provider.example.org
• app.example.org — application-side URLs (redirect_uri/callbacks, CLI login page)
• test@example.org — test account email

Domains removed: app.com (13×), provider.com (2×), other.com, test.com (incl. test@test.com).

Files Changed

• tests/config/itkdev_openid_connect.yml - provider metadata + redirect URIs
• tests/Security/OpenIdConfigurationProviderManagerTest.php - callback URIs
• tests/Security/OpenIdLoginAuthenticatorTest.php - test email
• tests/DependencyInjection/ConfigurationTest.php - redirect URIs + second provider metadata URL
• tests/Controller/LoginControllerTest.php - IdP authorization URL
• tests/Command/UserLoginCommandTest.php - CLI login URL (same change as test: pin down CLI login token lifecycle and URL generation #47; identical on both sides, so merges cleanly in either order)
• CHANGELOG.md - Unreleased bullet

Test Plan

• vendor/bin/phpunit — 83 tests, 184 assertions, green
• PHPStan max level, markdownlint, prettier (yaml) — clean
• grep -rE 'app\.com|provider\.com|other\.com|test\.com' tests/ src/ README.md — no matches

Notes

• Pre-existing example.com metadata URLs (already RFC 2606-compliant) were left unchanged
• Overlaps with open PRs test: pin down CLI login token lifecycle and URL generation #47/test: verify provider key lookup, claims contract and redirect route args #48 on three test files; identical or trivially resolvable — I'll resolve any conflicts as they merge

🤖 Generated with Claude Code

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (79e62dc) to head (40681bc).

Additional details and impacted files

@@             Coverage Diff             @@
##             develop       #49   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
  Complexity        62        62           
===========================================
  Files              9         9           
  Lines            282       282           
===========================================
  Hits             282       282           

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

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