Typed argument shapes: @phpstan-type aliases (unsealed + enum literals) for high-arity builders

[edpittol]

Summary

Converts the loosely-typed array<string, mixed> overrides/criteria params on the WooCommerce Method Traits' high-arity, error-prone builders into unsealed @phpstan-type array shapes with enum literals for status/stock/discount values:

• ProductMethods::haveProductInDatabase / haveManyProductsInDatabase — ProductOverrides (nested ProductMeta, ProductStatus, ProductStockStatus, ProductTaxStatus, ProductBackorders enums).
• CouponMethods::haveCouponInDatabase and its havePercentageCouponInDatabase/haveFixedCartCouponInDatabase/haveFixedProductCouponInDatabase/haveFreeShippingCouponInDatabase wrappers — CouponOverrides (nested CouponMeta, CouponStatus, CouponDiscountType enums).
• OrderMethods::haveOrderInDatabase / haveManyOrdersInDatabase — OrderOverrides (OrderStatus enum, nested address/items/meta).
• OrderMethods::haveOrderAddressInDatabase / seeOrderAddressInDatabase — OrderAddress shape + OrderAddressType enum.
• OrderMethods::haveOrderItemInDatabase (the order-item builder) — OrderItemOverrides with an OrderItemType enum.

All shapes are unsealed (...) so the merge-defaults pass-through pattern keeps working and legitimate extra keys aren't rejected. Trivial 2-3 key criteria params (meta lookups, simple ID/field queries) were left as prose @param, per scope. No @example blocks were added or rewritten.

Two defensive runtime checks in CouponMethods and ProductMethods that tested for array/string-ness of now-strictly-typed keys were simplified, since PHPStan flagged them as always-true/always-false once the shapes made the guarantee static.

Note: issue #35 (the cold-agent eval this issue's "Blocked by" pointed at) is closed, but its failure-log Cest was never actually committed to the repo — there's no tests/acceptance/*Cest.php recording the specific hallucinated keys. The shapes here were instead derived directly from each builder's existing implementation and are validated against the Cests that do exist (ProductCest, CouponCest, OrderCest, OrderHPOSCest).

Closes #37

Test plan

• vendor/bin/phpstan analyse — no errors (level max over src and tests)
• vendor/bin/phpcs — clean
• vendor/bin/codecept run unit — 32/32 passing
• vendor/bin/codecept run acceptance (via pre-push hook, full suite) — 198/198 passing