enhanced submission handling with deccision trees

lib/app_answers.php

@@ -48,6 +48,26 @@ function qdb_decode_multi_check_values(?string $raw): array {
     return [$trimmed];
 }
 
+/**
+ * Build glass-scale symptom JSON from the current submit only (no merge with prior rows).
+ *
+ * @param array<string, string> $symptomLabels symptom key => selected label
+ */
+function qdb_build_glass_symptom_json(array $symptomLabels): ?string {
+    $data = [];
+    foreach ($symptomLabels as $key => $label) {
+        $k = trim((string)$key);
+        $v = trim((string)$label);
+        if ($k !== '' && $v !== '') {
+            $data[$k] = $v;
+        }
+    }
+    if ($data === []) {
+        return null;
+    }
+    return json_encode($data, JSON_UNESCAPED_UNICODE);
+}
+
 /**
  * Group raw POST answer rows by question short id; merge multi_check option keys.
  *