Fix implicit nullable parameters deprecated in PHP 8.4

[matasarei]

What and why

ScopesMapper::__construct(Scopes $defaultScopes = null) and ItemsListResponse::__construct(array $items = [], int $total = null) declare implicitly nullable parameters. PHP 8.4 reports this as deprecated every time either class loads.

This library's suite never saw it, because PHPUnit 9 does not fail on deprecations by default. Downstream it does fail: grinchenkoedu/registries prints the notice from inside its tests, and its PHP 8.4 CI job fails under failOnRisky. That is the last cause left in registries#64.

How

• Both parameters are now explicitly nullable (?Scopes, ?int). No behaviour change.
• phpunit.xml sets convertDeprecationsToExceptions="true", so the next deprecation fails this CI instead of a downstream one. The file keeps its CRLF line endings; the change is one line.

Testing

• With only the guard in place, the suite on PHP 8.4.10 (composer:lts image) gave Tests: 46, Assertions: 121, Errors: 15, all from ScopesMapper.php:15.
• With the fix:
  • PHP 8.4 and 8.5 (stock images): OK (46 tests, 297 assertions).
  • PHP 7.4.3 (Composer install inside 7.4): OK (46 tests, 297 assertions).
• No implicit nullable is left in src/ or tests/ (grep).

Notes

• CHANGELOG has a 2.0.1 — unreleased entry. Once this is merged, tag 2.0.1 so registries can require ^2.0.1 when it moves to 2.0 (its Phase B, step 6).

Update after review

• The guard now fires in CI (ad97ede). setup-php loads the production php.ini (ini-file: production in the job logs), whose error_reporting leaves out E_DEPRECATED, and PHPUnit 9 only converts errors that error_reporting includes. So convertDeprecationsToExceptions had no effect in CI. With the ScopesMapper fix reverted, the suite at CI's level passed: OK (46 tests, 297 assertions). phpunit.xml now sets error_reporting to -1. At CI's level, the unfixed code now gives Errors: 15 and the fixed code OK (46 tests, 297 assertions).

  • Trade-off: the guard also covers dependencies, and CI resolves them fresh on every run, including the monthly one. A future dependency release that triggers a deprecation would turn CI red with no change here.

• .gitignore (218a24b): ignores .tasks/, .claude/repo-profile.json and .gku/, which are local plans and tool state. CRLF, like the rest of the file.

• First catch (55ecd8a): once the guard was active, the PHP 7.4 job failed with 5 errors. ClientFactoryTest cast ReflectionType to a string, which is deprecated on 7.4 only. It now uses getName(). All 7 PHP jobs pass on 55ecd8a.