[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/WhistleblowingController.php

@@ -238,7 +238,7 @@ class WhistleblowingController extends BaseController
         }
 
         if (!empty($updates)) {
-            Database::execute(
+            Database::query(
                 'UPDATE whistleblowing_reports SET ' .
                 implode(', ', array_map(fn($k) => "{$k} = ?", array_keys($updates))) .
                 ', updated_at = NOW() WHERE id = ?',
@@ -265,7 +265,7 @@ class WhistleblowingController extends BaseController
         if (!$report) { $this->jsonError('Segnalazione non trovata', 404, 'NOT_FOUND'); }
 
         $userId = (int)$this->getParam('user_id');
-        Database::execute(
+        Database::query(
             'UPDATE whistleblowing_reports SET assigned_to = ?, updated_at = NOW() WHERE id = ?',
             [$userId, $id]
         );
@@ -295,7 +295,7 @@ class WhistleblowingController extends BaseController
         if (!$report) { $this->jsonError('Segnalazione non trovata', 404, 'NOT_FOUND'); }
 
         $resolution = trim($this->getParam('resolution_notes', ''));
-        Database::execute(
+        Database::query(
             'UPDATE whistleblowing_reports SET status = "closed", closed_at = NOW(),
              closed_by = ?, resolution_notes = ?, updated_at = NOW() WHERE id = ?',
             [$this->getCurrentUserId(), $resolution, $id]