Refactor stats variable names for clarity

Renamed generic 'stats' variables to more specific names such as 'domainStats', 'errorStats', 'tldStats', and 'importStats' across controllers and views. This improves code readability and reduces ambiguity when handling different types of statistics in the application.

app/Controllers/TldRegistryController.php

@@ -37,12 +37,12 @@ class TldRegistryController extends Controller
         $order = $_GET['order'] ?? 'asc';
 
         $result = $this->tldModel->getPaginated($page, $perPage, $search, $sort, $order, $status, $dataType);
-        $stats = $this->tldModel->getStatistics();
+        $tldStats = $this->tldModel->getStatistics();
 
         $this->view('tld-registry/index', [
             'tlds' => $result['tlds'],
             'pagination' => $result['pagination'],
-            'stats' => $stats,
+            'tldStats' => $tldStats,
             'filters' => [
                 'search' => $search,
                 'status' => $status,
@@ -584,7 +584,7 @@ class TldRegistryController extends Controller
         $this->view('tld-registry/import-logs', [
             'imports' => $result['logs'],
             'pagination' => $result['pagination'],
-            'stats' => $importStats,
+            'importStats' => $importStats,
             'title' => 'TLD Import Logs'
         ]);
     }