Fix type safety and TDS class naming issues

- bulk_operation.php: replace is_numeric() with strict int cast+equality to reject scientific notation
- AttachmentModel.php: fix bind_param type strings (s→i for integer ticket IDs)
- CommentModel.php: use strict !== comparison with (int) cast for user_id ownership checks
- ticket.js: replace all non-TDS class names (text-amber→lt-text-amber, btn→lt-btn variants, etc.)

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

api/bulk_operation.php

@@ -50,12 +50,14 @@ if (!$operationType || empty($ticketIds)) {
     exit;
 }
 
-// Validate ticket IDs are integers
-foreach ($ticketIds as $ticketId) {
-    if (!is_numeric($ticketId)) {
-        echo json_encode(['success' => false, 'error' => 'Invalid ticket ID format']);
-        exit;
-    }
+// Validate ticket IDs are positive integers
+$ticketIds = array_values(array_filter(array_map(function($id) {
+    $int = (int)$id;
+    return ($int > 0 && (string)$int === (string)$id) ? $int : null;
+}, $ticketIds)));
+if (empty($ticketIds)) {
+    echo json_encode(['success' => false, 'error' => 'No valid ticket IDs provided']);
+    exit;
 }
 
 // Use centralized database connection