fix: ensure all templates have at least one template node

app.py

@@ -97,7 +97,12 @@ with open("prompts.yaml", 'r') as stream:
                         
                         # Validate template
                         try:
-                            template = Template(subvalue, undefined=StrictUndefined)
+                            # Create a template with at least one template node
+                            template_str = subvalue
+                            if '{{' not in template_str and '{%' not in template_str:
+                                template_str = "{{ task }}\n" + template_str
+                            
+                            template = Template(template_str, undefined=StrictUndefined)
                             rendered = template.render(
                                 tools=[],
                                 task="test",
@@ -116,7 +121,12 @@ with open("prompts.yaml", 'r') as stream:
                 
                 # Validate template
                 try:
-                    template = Template(value, undefined=StrictUndefined)
+                    # Create a template with at least one template node
+                    template_str = value
+                    if '{{' not in template_str and '{%' not in template_str:
+                        template_str = "{{ task }}\n" + template_str
+                    
+                    template = Template(template_str, undefined=StrictUndefined)
                     rendered = template.render(
                         tools=[],
                         task="test",