[ogorzalka]

Raises the coverage of the package from 54.2 % to 98.8 %, with tests only (src/ is untouched).

184 test cases in four files (the suite goes from 77 to 261): every fluent accessor of Entity, PostType and Taxonomy keeps its value and stays chainable (datasets), and the fallbacks to register_post_type / register_taxonomy. Entity, PostType and Taxonomy are at 100 %. In tests/Helpers/helpers.php the global register_post_type and register_taxonomy stand-ins now also record their calls in $GLOBALS['entity_test_registrations'] (four lines added, none removed; no other test reads it).

Not covered: PostTypeRegistryAdapter (83.3 %: lines 44, 51, 65) and TaxonomyRegistryAdapter (88.9 %: lines 53, 68), the branches taken when the WordPress or Extended CPTs registration functions do not exist. A global function cannot be removed in a running process, and johnbillion/extended-cpts defines its own through the Composer autoload.

Seen in the code and left as it is:

• TaxonomyRegistryAdapter::register() does unset($args['object_type']) after calling registerTaxonomy, which has no effect ($args is not used again), and a call without object_type is ignored without an error or a message (a test pins it).
• Entity::showInMenu() has no return type, unlike its neighbours (: self).
• The composer phpstan script analyses tests too and reports 57 errors that are already on main (deprecated calls in the existing tests); the CI uses phpstan.neon (src only), which is clean.

The coverage ratchet in .harness.json goes from 54.23 to 98. Measured with pest --coverage (PHP 8.4, pcov, the CI driver); the 261 tests pass in random orders; Pint, PHPStan, Rector (--dry-run) and tests/Arch.php are clean.