fix: Update CustomCodeAgent to use Jinja2 template rendering

app.py

@@ -243,8 +243,8 @@ class CustomCodeAgent(CodeAgent):
     def initialize_system_prompt(self):
         # Override to use tools_dict for template rendering
         template = self.prompt_templates["system_prompt"]
-        # Use getattr to safely access attributes that might not be set yet
-        return template.format(
+        # Use Jinja2 template rendering
+        return Template(template, undefined=StrictUndefined).render(
             tools=self.tools_dict,
             task=getattr(self, 'task', ''),
             managed_agents=getattr(self, 'managed_agents', []),