fix: Zoho CRM admin menu visibility - use admin_menu hook

Changed initializeAdminComponents hook from admin_init to admin_menu
with priority 5. WordPress fires admin_menu before admin_init, so
the Zoho admin submenu was being registered too late to appear.

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

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

includes/class-hvac-plugin.php

@@ -548,7 +548,8 @@ final class HVAC_Plugin {
         // Schedule non-critical components for lazy loading
         // Use 'init' instead of 'wp_loaded' so components can register wp_enqueue_scripts hooks
         add_action('init', [$this, 'initializeSecondaryComponents'], 5);
-        add_action('admin_init', [$this, 'initializeAdminComponents'], 5);
+        // Use admin_menu (not admin_init) so components can register their menus in time
+        add_action('admin_menu', [$this, 'initializeAdminComponents'], 5);
     }
     
     /**