Fix AtrributeError

✅ Solution

The "AttributeError" in Panel often arises when a widget's underlying model hasn't been fully initialized, particularly when using `.from_param` or saving to HTML. Ensure all necessary parameters, especially those required by the widget's `__init__` method or model properties, are provided during widget creation or before saving. Explicitly set default values or use `param.parameterized.parameter_kwargs` to preemptively populate missing attributes.