Fix code quality issues and improve test framework

includes/Multisite/class-multisite.php

@@ -36,7 +36,7 @@ class Multisite {
      *
      * @return bool Always returns true.
      */
-    public function is_multisite_compatible() {
+    public function isMultisiteCompatible() {
         return true;
     }
 
@@ -45,9 +45,9 @@ class Multisite {
      *
      * @return array An empty array as this is just a placeholder.
      */
-    public function get_network_sites() {
+    public function getNetworkSites() {
         // This is just a placeholder method.
         // In a real implementation, you might use get_sites() or a custom query.
-        return array();
+        return function_exists('get_sites') ? get_sites(['public' => 1]) : array();
     }
 }