Add test infrastructure for isolated unit testing without WordPress/WooCommerce:
- 27 tests (54 assertions) covering TemplateOverride and WooCommerceExtension
- Brain\Monkey for WordPress function mocking, class stubs for TwigService and WC_Product
- PHPUnit test job added to Gitea CI pipeline between lint and build-release
- Test artifacts excluded from release packages
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add constraints section documenting that the woocommerce plugin is read-only
and that the Docker environment is not yet set up. Track composer.lock.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>