Add bulk transfer functionality for domains and groups

Introduces bulk transfer for domains and groups, available only to admins. Refactors admin checks to use isAdmin(), adds user selection for transfers, and updates views to include transfer buttons and modals for domain transfers.

app/Controllers/DomainController.php

@@ -64,10 +64,18 @@ class DomainController extends Controller
         // Format domains for display
         $formattedDomains = \App\Helpers\DomainHelper::formatMultiple($result['domains']);
 
+        // Get users for transfer functionality (admin only)
+        $users = [];
+        if (\Core\Auth::isAdmin()) {
+            $userModel = new \App\Models\User();
+            $users = $userModel->all();
+        }
+
         $this->view('domains/index', [
             'domains' => $formattedDomains,
             'groups' => $groups,
             'allTags' => $allTags,
+            'users' => $users,
             'filters' => [
                 'search' => $search,
                 'status' => $status,

app/Controllers/NotificationGroupController.php

@@ -33,7 +33,7 @@ class NotificationGroupController extends Controller
 
         // Get users for transfer functionality (admin only)
         $users = [];
-        if (\Core\Auth::user()['role'] === 'admin') {
+        if (\Core\Auth::isAdmin()) {
             $userModel = new \App\Models\User();
             $users = $userModel->all();
         }

app/Views/domains/index.php

@@ -132,6 +132,13 @@ $currentFilters = $filters ?? ['search' => '', 'status' => '', 'group' => '', 's
                 Refresh Selected
             </button>
             
+            <?php if (\Core\Auth::isAdmin()): ?>
+                <button type="button" onclick="bulkTransfer()" class="inline-flex items-center px-4 py-2 bg-indigo-600 text-white text-sm rounded-lg hover:bg-indigo-700 transition-colors font-medium">
+                    <i class="fas fa-exchange-alt mr-2"></i>
+                    Transfer Selected
+                </button>
+            <?php endif; ?>
+            
             <div class="relative inline-block">
                 <button type="button" onclick="toggleAssignTagsDropdown()" class="inline-flex items-center px-4 py-2 bg-purple-600 text-white text-sm rounded-lg hover:bg-purple-700 transition-colors font-medium">
                     <i class="fas fa-tags mr-2"></i>
@@ -725,6 +732,62 @@ function bulkRemoveAllTags() {
     form.submit();
 }
 
+// Bulk transfer domains
+function bulkTransfer() {
+    const ids = getSelectedIds();
+    if (ids.length === 0) {
+        alert('Please select at least one domain');
+        return;
+    }
+    
+    // Get list of users for transfer
+    const users = <?= json_encode($users ?? []) ?>;
+    if (users.length === 0) {
+        alert('No users available for transfer');
+        return;
+    }
+    
+    // Create user selection options
+    let userOptions = users.map(user => 
+        `<option value="${user.id}">${user.username} (${user.full_name || user.email})</option>`
+    ).join('');
+    
+    const modal = document.createElement('div');
+    modal.className = 'fixed inset-0 bg-gray-600 bg-opacity-50 overflow-y-auto h-full w-full z-50';
+    modal.innerHTML = `
+        <div class="relative top-20 mx-auto p-5 border w-96 shadow-lg rounded-md bg-white">
+            <div class="mt-3">
+                <h3 class="text-lg font-medium text-gray-900 mb-4">Transfer ${ids.length} Domain(s)</h3>
+                <p class="text-sm text-gray-500 mb-4">Select the user to transfer the selected domains to:</p>
+                
+                <form method="POST" action="/domains/bulk-transfer">
+                    <input type="hidden" name="csrf_token" value="<?= csrf_token() ?>">
+                    ${ids.map(id => `<input type="hidden" name="domain_ids[]" value="${id}">`).join('')}
+                    
+                    <div class="mb-4">
+                        <label for="target_user_id" class="block text-sm font-medium text-gray-700 mb-2">Transfer to User:</label>
+                        <select name="target_user_id" id="target_user_id" required class="w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500">
+                            <option value="">Select a user...</option>
+                            ${userOptions}
+                        </select>
+                    </div>
+                    
+                    <div class="flex justify-end space-x-3">
+                        <button type="button" onclick="this.closest('.fixed').remove()" class="px-4 py-2 bg-gray-300 text-gray-700 rounded-md hover:bg-gray-400">
+                            Cancel
+                        </button>
+                        <button type="submit" class="px-4 py-2 bg-indigo-600 text-white rounded-md hover:bg-indigo-700">
+                            Transfer Domains
+                        </button>
+                    </div>
+                </form>
+            </div>
+        </div>
+    `;
+    
+    document.body.appendChild(modal);
+}
+
 // Update bulk assign form with selected IDs
 document.getElementById('bulk-assign-form')?.addEventListener('submit', function(e) {
     const ids = getSelectedIds();

app/Views/groups/index.php

@@ -37,7 +37,7 @@ ob_start();
         <div class="flex items-center gap-4">
             <span id="selected-count" class="text-sm font-medium text-blue-900"></span>
             
-            <?php if (\Core\Auth::user()['role'] === 'admin'): ?>
+            <?php if (\Core\Auth::isAdmin()): ?>
                 <button type="button" onclick="bulkTransfer()" class="inline-flex items-center px-4 py-2 bg-green-600 text-white text-sm rounded-lg hover:bg-green-700 transition-colors font-medium">
                     <i class="fas fa-exchange-alt mr-2"></i>
                     Transfer Selected
@@ -113,7 +113,7 @@ ob_start();
                                     <a href="/groups/edit?id=<?= $group['id'] ?>" class="text-blue-600 hover:text-blue-800" title="Manage">
                                         <i class="fas fa-cog"></i>
                                     </a>
-                                    <?php if (\Core\Auth::user()['role'] === 'admin'): ?>
+                                    <?php if (\Core\Auth::isAdmin()): ?>
                                         <button onclick="transferGroup(<?= $group['id'] ?>, '<?= htmlspecialchars($group['name']) ?>')" 
                                                 class="text-green-600 hover:text-green-800" 
                                                 title="Transfer Group">