Release version 1.1.15 - Fix duplicate settings page

Fixed settings page appearing twice in WooCommerce settings due to double instantiation of WC_TPP_Settings class.

**Issue:**
- Settings page rendered twice on same page
- WC_TPP_Settings class instantiated twice: once automatically in settings file, once via admin class include

**Fix:**
- Removed conditional wrapper `if (class_exists('WC_TPP_Settings'))` from settings return statement
- Settings class now only instantiated when admin class includes the file via `return new WC_TPP_Settings();`
- Restored v1.1.2 pattern for settings file

**Files Modified:**
- includes/class-wc-tpp-settings.php (simplified return statement)

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

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

wc-tier-and-package-prices.php

@@ -4,7 +4,7 @@
  * Plugin Name: WooCommerce Tier and Package Prices
  * Plugin URI: https://src.bundespruefstelle.ch/magdev/wc-tier-package-prices
  * Description: Add tier pricing and package prices to WooCommerce products with configurable quantities at fixed prices
- * Version: 1.1.14
+ * Version: 1.1.15
  * Author: Marco Graetsch
  * Author URI: https://src.bundespruefstelle.ch/magdev
  * Text Domain: wc-tier-package-prices
@@ -23,7 +23,7 @@ if (!defined('ABSPATH')) {
 
 // Define plugin constants
 if (!defined('WC_TPP_VERSION')) {
-    define('WC_TPP_VERSION', '1.1.14');
+    define('WC_TPP_VERSION', '1.1.15');
 }
 if (!defined('WC_TPP_PLUGIN_DIR')) {
     define('WC_TPP_PLUGIN_DIR', plugin_dir_path(__FILE__));