Add user isolation mode and transfer features

Introduces user isolation mode, allowing domains, groups, and tags to be visible only to their owners when enabled. Adds user_id fields to domains and notification_groups, updates models and controllers for isolation-aware queries, and provides admin UI and endpoints for transferring domains and groups between users (single and bulk). Includes migration, settings UI, and routes for toggling isolation mode and handling data migration.

app/Controllers/SearchController.php

@@ -27,12 +27,17 @@ class SearchController extends Controller
             return;
         }
 
+        // Get current user and isolation mode
+        $userId = \Core\Auth::id();
+        $settingModel = new \App\Models\Setting();
+        $isolationMode = $settingModel->getValue('user_isolation_mode', 'shared');
+
         // Pagination parameters
         $page = max(1, (int)($_GET['page'] ?? 1));
         $perPage = max(10, min(100, (int)($_GET['per_page'] ?? 25)));
 
         // Search existing domains in database
-        $allResults = $this->searchDomains($query);
+        $allResults = $this->searchDomains($query, $isolationMode === 'isolated' ? $userId : null);
         $totalResults = count($allResults);
 
         // Calculate pagination
@@ -144,25 +149,47 @@ class SearchController extends Controller
     /**
      * Search domains in database
      */
-    private function searchDomains(string $query): array
+    private function searchDomains(string $query, ?int $userId = null): array
     {
         $db = \Core\Database::getConnection();
         $sql = "SELECT d.*, ng.name as group_name 
                 FROM domains d 
                 LEFT JOIN notification_groups ng ON d.notification_group_id = ng.id 
-                WHERE d.domain_name LIKE ? 
+                WHERE (d.domain_name LIKE ? 
                    OR d.registrar LIKE ?
-                   OR ng.name LIKE ?
-                ORDER BY d.domain_name ASC
-                LIMIT 50";
+                   OR ng.name LIKE ?)";
+        
+        $params = ['%' . $query . '%', '%' . $query . '%', '%' . $query . '%'];
+        
+        if ($userId && !$this->isAdmin($userId)) {
+            $sql .= " AND d.user_id = ?";
+            $params[] = $userId;
+        }
+        
+        $sql .= " ORDER BY d.domain_name ASC LIMIT 50";
 
-        $searchTerm = '%' . $query . '%';
         $stmt = $db->prepare($sql);
-        $stmt->execute([$searchTerm, $searchTerm, $searchTerm]);
+        $stmt->execute($params);
         
         return $stmt->fetchAll();
     }
 
+    /**
+     * Check if user is admin
+     */
+    private function isAdmin(?int $userId): bool
+    {
+        if (!$userId) {
+            return false;
+        }
+        
+        $db = \Core\Database::getConnection();
+        $stmt = $db->prepare("SELECT role FROM users WHERE id = ?");
+        $stmt->execute([$userId]);
+        $user = $stmt->fetch();
+        return $user && $user['role'] === 'admin';
+    }
+
     /**
      * Check if string looks like a domain name
      */