added categoryKey to questionnaire schema and updated related functions for questionnaire handling; enhanced API to fetch client answers

common.php

@@ -1172,8 +1172,9 @@ function qdb_import_questionnaire_bundle(PDO $pdo, array $item, bool $replaceIfE
         $condJson = json_encode($condJson, JSON_UNESCAPED_UNICODE);
     }
 
-    $pdo->prepare("INSERT INTO questionnaire (questionnaireID, name, version, state, orderIndex, showPoints, conditionJson)
-                   VALUES (:id, :n, :v, :s, :o, :sp, :cj)")
+    $catKey = trim($meta['categoryKey'] ?? '');
+    $pdo->prepare("INSERT INTO questionnaire (questionnaireID, name, version, state, orderIndex, showPoints, conditionJson, categoryKey)
+                   VALUES (:id, :n, :v, :s, :o, :sp, :cj, :ck)")
         ->execute([
             ':id' => $qnID,
             ':n'  => trim($meta['name']),
@@ -1182,6 +1183,7 @@ function qdb_import_questionnaire_bundle(PDO $pdo, array $item, bool $replaceIfE
             ':o'  => $order,
             ':sp' => (int)($meta['showPoints'] ?? 0),
             ':cj' => $condJson ?: '{}',
+            ':ck' => $catKey,
         ]);
 
     foreach ($item['questions'] ?? [] as $q) {