Ensure that all mocked dependencies in RegisterCustomerTest are properly bound
to the Laravel service container using App::instance(). This prevents any code
that resolves dependencies via container injection from getting real service
instances instead of mocks.
This fix aligns the Integration test pattern with Feature tests which already
use App::instance() to bind mocks to the container.
Changes:
- Add import for Illuminate\Support\Facades\App
- Add App::instance() calls after each mock creation in all 6 test cases
- Add mockCrmService() helper method to TestCase base class for future tests
Fixes CI failures where CRM service was being called in real instead of being mocked.
