* devops: Product and product attribute mutation tests generated
* feat: Product Mutations implemented and tested
* chore: Linter and PHPStan compliance met
* fix: resolve test failures in product and variation mutation tests
- Removed duplicate requires for payment-method classes (rebase artifact)
- Wrapped bare `attributes` queries in `... on SimpleProduct` inline
fragments (attributes field is on ProductWithAttributes interface,
not the base Product type)
- Fixed attribute label expectations to match factory output (lowercase)
- Fixed relay ID prefix from 'product'/'product_variation' to 'post'
to match WPGraphQL's actual encoding
- Cache WP_Post before force-deletion and re-cache after so the Product
model's type resolver can still determine the GraphQL type in the
response
- Added wp_cache_flush() before asserting product deletion to avoid
false positives from the re-cached post
* chore: fix PHPCS lint errors in mutation files
* fix: resolve CI test failures for attribute and variation mutations
- Fixed ProductVariation type registration in schema filters so the
variation mutation output field resolves correctly
- Renamed attribute slug from 'pattern' to 'fabric' in
ProductAttributeMutationsTest to avoid collision with the pattern
attribute created by ProductAttributeQueriesTest
- Fixed PHPStan errors for redundant is_wp_error checks
- Updated IntrospectionQueryTest
