Security/correctness: visibility filtering, Content-Type headers, group validation

- TicketModel::getAllTickets() now accepts optional $user param and applies
  getVisibilityFilter() so non-admin users cannot see internal/confidential
  tickets they lack access to from the dashboard listing
- DashboardController passes $GLOBALS['currentUser'] to getAllTickets()
- clone_ticket.php: move Content-Type header to top so all error paths send
  correct JSON content type
- AuthMiddleware: filter group names from HTTP header to [a-z0-9_-] only,
  preventing header injection via malformed group names
- add_comment.php: return HTTP 201 on success, 500 in catch block
- update_comment.php, delete_comment.php: return 500 in catch blocks

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

api/add_comment.php

@@ -138,6 +138,9 @@ try {
     ob_end_clean();
 
     // Return JSON response
+    if ($result['success']) {
+        http_response_code(201);
+    }
     header('Content-Type: application/json');
     echo json_encode($result);
 
@@ -149,6 +152,7 @@ try {
     error_log("Add comment API error: " . $e->getMessage());
 
     // Return error response
+    http_response_code(500);
     header('Content-Type: application/json');
     echo json_encode([
         'success' => false,

api/clone_ticket.php

@@ -7,6 +7,8 @@
 ini_set('display_errors', 0);
 error_reporting(E_ALL);
 
+header('Content-Type: application/json');
+
 require_once dirname(__DIR__) . '/middleware/RateLimitMiddleware.php';
 RateLimitMiddleware::apply('api');
 
@@ -109,7 +111,6 @@ try {
         $dependencyModel = new DependencyModel($conn);
         $dependencyModel->addDependency($result['ticket_id'], $sourceTicketId, 'relates_to', $userId);
 
-        header('Content-Type: application/json');
         echo json_encode([
             'success' => true,
             'new_ticket_id' => $result['ticket_id'],

api/delete_comment.php

@@ -115,6 +115,7 @@ try {
 } catch (Exception $e) {
     ob_end_clean();
     error_log("Delete comment API error: " . $e->getMessage());
+    http_response_code(500);
     header('Content-Type: application/json');
     echo json_encode([
         'success' => false,

api/update_comment.php

@@ -104,6 +104,7 @@ try {
 } catch (Exception $e) {
     ob_end_clean();
     error_log("Update comment API error: " . $e->getMessage());
+    http_response_code(500);
     header('Content-Type: application/json');
     echo json_encode([
         'success' => false,

controllers/DashboardController.php

@@ -142,7 +142,7 @@ class DashboardController {
         if ($assignedTo !== null) $filters['assigned_to'] = $assignedTo;
 
         // Get tickets with pagination, sorting, search, and advanced filters
-        $result = $this->ticketModel->getAllTickets($page, $limit, $status, $sortColumn, $sortDirection, $category, $type, $search, $filters);
+        $result = $this->ticketModel->getAllTickets($page, $limit, $status, $sortColumn, $sortDirection, $category, $type, $search, $filters, $GLOBALS['currentUser'] ?? []);
 
         // Get categories and types for filters (single query)
         $filterOptions = $this->getCategoriesAndTypes();

middleware/AuthMiddleware.php

@@ -155,7 +155,11 @@ class AuthMiddleware {
         }
 
         // Check for admin or employee group membership
-        $userGroups = array_map('trim', explode(',', strtolower($groups)));
+        // Filter to safe characters only to prevent header injection attacks
+        $userGroups = array_filter(
+            array_map('trim', explode(',', strtolower($groups))),
+            function($g) { return preg_match('/^[a-z0-9_\-]+$/', $g); }
+        );
         $requiredGroups = ['admin', 'employee'];
 
         return !empty(array_intersect($userGroups, $requiredGroups));

models/TicketModel.php

@@ -31,7 +31,7 @@ class TicketModel {
         return $result->fetch_assoc();
     }
     
-    public function getAllTickets(int $page = 1, int $limit = 15, ?string $status = 'Open', string $sortColumn = 'ticket_id', string $sortDirection = 'desc', ?string $category = null, ?string $type = null, ?string $search = null, array $filters = []): array {
+    public function getAllTickets(int $page = 1, int $limit = 15, ?string $status = 'Open', string $sortColumn = 'ticket_id', string $sortDirection = 'desc', ?string $category = null, ?string $type = null, ?string $search = null, array $filters = [], ?array $user = null): array {
         // Calculate offset
         $offset = ($page - 1) * $limit;
 
@@ -40,6 +40,16 @@ class TicketModel {
         $params = [];
         $paramTypes = '';
 
+        // Visibility filtering
+        if ($user !== null) {
+            $visFilter = $this->getVisibilityFilter($user);
+            if ($visFilter['sql'] !== '1=1') {
+                $whereConditions[] = $visFilter['sql'];
+                $params = array_merge($params, $visFilter['params']);
+                $paramTypes .= $visFilter['types'];
+            }
+        }
+
         // Status filtering
         if ($status) {
             $statuses = explode(',', $status);