[ichinya]

Rector currently recognises PHPUnit assertion methods by call shape and name. A project method such as assertSame() or assertIsString() can therefore be rewritten even when it has its own implementation and return value.

Require the resolved method declaration to belong to PHPUnit's Assert or TestCase. Custom, inherited custom, magic, trait-required and unresolved methods stay unchanged. PHPUnit assertion functions keep their namespace-based recognition.

Only the shared assertion recogniser changes in production. The broad fixture edit adds PHPUnit ancestry to 33 existing method-call fixtures; function-call fixtures retain their existing ancestry. Reflection-only PHPUnit declarations are scanned by PHPStan without loading fake runtime classes into Double or other bridges.

Validation:

• PHP 8.2.34, 8.3.35 and 8.5.11: all 927 relevant checks pass on each runtime (362 Rector fixtures, 171 harness unit tests and 394 Assert tests). PHP 8.2 was explicitly tested.
• PHP 8.5 full regular suite: passed, 2926 tests and 5849 assertions; no failures or errors, one flaky and two skipped.
• Changed-file CS Fixer and git diff checks pass.
• Combined with fix(rector): preserve string assertion call contracts #396: merges without conflicts and the full regular suite passes (2930 tests, 5853 assertions, no failures or errors).

Part of #390. Named string arguments, weak/strict coercion and evaluation order are handled in #396. Both PRs target 1.x independently; review this ownership change first.