fix: PHP errors and clean up error_log statements

- Fixed redirect_wc_pages_to_spa: added spa_mode check (only redirect when 'full')
- Fixed PHP fatal error: use get_queried_object() instead of global $product
- Removed all error_log debug statements from codebase
- Fixed broken syntax in PaymentGatewaysProvider.php after error_log removal

includes/Admin/StandaloneAdmin.php

@@ -53,9 +53,6 @@ class StandaloneAdmin {
 		
 		// Debug logging (only in WP_DEBUG mode)
 		if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
-			error_log( '[StandaloneAdmin] is_user_logged_in: ' . ( $is_logged_in ? 'true' : 'false' ) );
-			error_log( '[StandaloneAdmin] has manage_woocommerce: ' . ( $has_permission ? 'true' : 'false' ) );
-			error_log( '[StandaloneAdmin] is_authenticated: ' . ( $is_authenticated ? 'true' : 'false' ) );
 		}
 		
 		// Get nonce for REST API