chore: Remove CTA A/B Testing legacy system

This feature was not part of the current development phase.

Deleted files:
- Inc/cta-ab-testing.php (A/B testing implementation)
- Inc/customizer-cta.php (WordPress Customizer settings + Google Analytics)
- TemplateParts/content-cta.php (CTA template part)
- Assets/Js/cta-tracking.js (GA4 tracking script)

Modified files:
- functions.php: Remove require_once for deleted files
- functions-addon.php: Remove CTA loading references
- Inc/enqueue-scripts.php: Remove roi_enqueue_cta_assets() function

Note: CTA components in Admin Panel (CtaBoxSidebar, CtaLetsTalk, CtaPost)
are NOT affected - they are part of the Clean Architecture system.

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

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

inc/enqueue-scripts.php

@@ -505,45 +505,6 @@ function roi_enqueue_apu_tables_autoclass_script() {
 
 add_action('wp_enqueue_scripts', 'roi_enqueue_apu_tables_autoclass_script', 15);
 
-/**
- * Enqueue CTA A/B Testing styles and scripts
- */
-function roi_enqueue_cta_assets() {
-    // Solo enqueue en posts individuales
-    if (!is_single()) {
-        return;
-    }
-
-    // Verificar si el CTA está habilitado
-    $enable_cta = get_theme_mod('roi_enable_cta', true);
-    if (!$enable_cta) {
-        return;
-    }
-
-    // CTA CSS
-    wp_enqueue_style(
-        'roi-cta-style',
-        get_template_directory_uri() . '/Assets/css/componente-cta-ab-testing.css',
-        array('roi-bootstrap'),
-        ROI_VERSION,
-        'all'
-    );
-
-    // CTA Tracking JS
-    wp_enqueue_script(
-        'roi-cta-tracking',
-        get_template_directory_uri() . '/Assets/js/cta-tracking.js',
-        array(),
-        ROI_VERSION,
-        array(
-            'in_footer' => true,
-            'strategy'  => 'defer',
-        )
-    );
-}
-
-add_action('wp_enqueue_scripts', 'roi_enqueue_cta_assets', 16);
-
 /**
  * Enqueue CTA Box Sidebar styles (Issue #36)
  *