- Consolidate JSON serialization for assistant fields into a single function, `marshalJSONFields`, to streamline the code and improve maintainability.
- Introduce a new utility function, `isNil`, to accurately check for nil values, including typed nils in interface{} types.
- Remove redundant marshaling logic for options, tags, and modes, enhancing clarity and reducing code duplication.
- Update the `UpdateAssistant` method to utilize the new nil-checking logic for JSON fields, ensuring correct handling of nil values.
1b60feacab