Enhance email rendering and Jira widget functionality

- Implemented a secure rendering method for email content using a sandboxed iframe to prevent XSS attacks.
- Added thorough HTML sanitization for incoming emails to mitigate potential exploits.
- Refactored email body rendering logic to utilize a dedicated function for better readability and maintainability.
- Updated Jira widget to fetch and display dashboard data, including assigned issues and team issues, with improved filtering options.
- Enhanced the user interface of the Jira widget with a standardized control toolbar for resizing and collapsing widgets.
- Introduced inline search functionality within the Jira widget for quick ticket filtering.
- Improved error handling and logging for Jira data fetching.

api/webhooks/jira.php

@@ -4,16 +4,28 @@
  * Ontvangt webhook events van Atlassian Jira Cloud (issue_created, issue_updated, etc.)
  */
 
+require_once __DIR__ . '/../../config/config.php';
 require_once __DIR__ . '/../../config/database.php';
 
 header('Content-Type: application/json');
 
+// Beveiligingscontrole: Verifieer geheime webhook token indien geconfigureerd in .env
+$configuredSecret = fociz_env('JIRA_WEBHOOK_SECRET', '');
+if (!empty($configuredSecret)) {
+    $incomingSecret = $_GET['secret'] ?? ($_SERVER['HTTP_X_ATLASSIAN_WEBHOOK_SECRET'] ?? '');
+    if (!hash_equals($configuredSecret, $incomingSecret)) {
+        http_response_code(401);
+        echo json_encode(['error' => 'Onbevoegde webhook aanroep']);
+        exit;
+    }
+}
+
 $rawPayload = file_get_contents('php://input');
 $data = json_decode($rawPayload, true);
 
 if (!$data) {
     http_response_code(400);
-    echo json_encode(['error' => 'Invalid JSON payload']);
+    echo json_encode(['error' => 'Ongeldige JSON payload']);
     exit;
 }