debug: Add comprehensive logging to trace route registration

Added logging at 3 critical points:
1. rest_api_init hook firing
2. Before ProductsController::register_routes()
3. After ProductsController::register_routes()
4. Inside ProductsController::get_products()

This will show us:
- Is rest_api_init hook firing?
- Is ProductsController being registered?
- Is get_products() being called when we hit /products?

Expected log sequence:
1. WooNooW Routes: rest_api_init hook fired
2. WooNooW Routes: Registering ProductsController routes
3. WooNooW Routes: ProductsController routes registered
4. WooNooW ProductsController::get_products() CALLED (when API called)

If any are missing, we know where the problem is.

includes/Api/ProductsController.php

@@ -85,6 +85,7 @@ class ProductsController {
 	 * Get products list with filters
 	 */
 	public static function get_products(WP_REST_Request $request) {
+		error_log('WooNooW ProductsController::get_products() CALLED');
 		$page = max(1, (int) $request->get_param('page'));
 		$per_page = min(100, max(1, (int) ($request->get_param('per_page') ?: 20)));
 		$search = $request->get_param('search');