[FIX] Database::execute() → Database::query() in 5 controller

Database non ha metodo execute() — corretto in:
InviteController, ServicesController, WebhookController,
NormativeController, WhistleblowingController.
Causa del HTTP 500 su tutti gli endpoint /api/invites/*.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

application/controllers/WebhookController.php

@@ -146,7 +146,7 @@ class WebhookController extends BaseController
             $this->jsonError('API Key non trovata', 404, 'NOT_FOUND');
         }
 
-        Database::execute(
+        Database::query(
             'UPDATE api_keys SET is_active = 0, updated_at = NOW() WHERE id = ?',
             [$id]
         );
@@ -273,7 +273,7 @@ class WebhookController extends BaseController
         if (!empty($updates)) {
             $updates['updated_at'] = date('Y-m-d H:i:s');
             $setClauses = implode(', ', array_map(fn($k) => "{$k} = ?", array_keys($updates)));
-            Database::execute(
+            Database::query(
                 "UPDATE webhook_subscriptions SET {$setClauses} WHERE id = ?",
                 array_merge(array_values($updates), [$id])
             );
@@ -297,7 +297,7 @@ class WebhookController extends BaseController
             $this->jsonError('Webhook non trovato', 404, 'NOT_FOUND');
         }
 
-        Database::execute('DELETE FROM webhook_subscriptions WHERE id = ?', [$id]);
+        Database::query('DELETE FROM webhook_subscriptions WHERE id = ?', [$id]);
         $this->logAudit('webhook_deleted', 'webhook_subscription', $id, ['name' => $sub['name']]);
         $this->jsonSuccess(null, 'Webhook eliminato');
     }