changes

app/workflow_utils.py

@@ -321,17 +321,34 @@ def resolve_value(expr, context):
     # =============================================
     # $append(list, element)
     if re.match(r'^\$append\(', expr, re.IGNORECASE):
-        match = re.match(r'^\$append\((.*)\)$', expr, re.IGNORECASE)
+        match = re.match(r"^\$append\(([^,]+),\s*(.+)\)$", expr, re.DOTALL)
         if match:
-            args = split_args(match.group(1))
-            if len(args) == 2:
-                target_list = resolve_value(args[0], context)
-                element = resolve_value(args[1], context)
-                if not isinstance(target_list, list):
-                    target_list = []
-                result = list(target_list)
-                result.append(element)
-                return result
+            list_expr = match.group(1).strip()
+            element_expr = match.group(2).strip()
+
+            # 1. Resolve the list
+            target_list = resolve_value(list_expr, context)
+            if target_list is None:
+                target_list = []
+            
+            # Ensure it's a copy so we don't modify the original context variable directly
+            target_list = list(target_list) 
+
+            # 2. Resolve the element
+            resolved_element = resolve_value(element_expr, context)
+
+            if isinstance(resolved_element, str):
+                try:
+                    import json
+                    element_to_append = json.loads(resolved_element)
+                except json.JSONDecodeError:
+                    element_to_append = resolved_element
+            else:
+                element_to_append = resolved_element
+            
+            target_list.append(element_to_append)
+            return target_list
+
 
     # $first(list), $last(list)
     if re.match(r'^\$(first|last)\(', expr, re.IGNORECASE):