Fix Settings.php class loading timing issue (v1.1.2)

CRITICAL BUG FIX: v1.1.1 still had the same error!

Root cause analysis:
- v1.1.1 changed hook to woocommerce_init but error persisted
- Real issue: Settings.php was require_once'd in Plugin::includes()
- At that point, class extends WC_Settings_Page which doesn't exist yet
- Even woocommerce_init fires before WC_Settings_Page is loaded

Solution:
- Removed require_once from Plugin::includes() (line 93)
- Moved require_once to Plugin::add_settings_page() (line 196)
- Settings.php now loads on-demand via woocommerce_get_settings_pages filter
- This filter fires when WooCommerce has loaded all settings classes

Changes:
- includes/Plugin.php: Delayed Settings.php inclusion with explanatory comment
- wc-composable-product.php: Version bump to 1.1.2
- CHANGELOG.md: Documented fix and noted v1.1.1 was insufficient

This addresses the actual root cause that persisted through 3 versions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

wc-composable-product.php

@@ -3,7 +3,7 @@
  * Plugin Name: WooCommerce Composable Products
  * Plugin URI: https://github.com/magdev/wc-composable-product
  * Description: Create composable products where customers select a limited number of items from a configurable set
- * Version: 1.1.1
+ * Version: 1.1.2
  * Author: Marco Graetsch
  * Author URI: https://example.com
  * License: GPL v3 or later
@@ -19,7 +19,7 @@
 defined('ABSPATH') || exit;
 
 // Define plugin constants
-define('WC_COMPOSABLE_PRODUCT_VERSION', '1.1.1');
+define('WC_COMPOSABLE_PRODUCT_VERSION', '1.1.2');
 define('WC_COMPOSABLE_PRODUCT_FILE', __FILE__);
 define('WC_COMPOSABLE_PRODUCT_PATH', plugin_dir_path(__FILE__));
 define('WC_COMPOSABLE_PRODUCT_URL', plugin_dir_url(__FILE__));