Enhance the Harness Workspace variable management experience by adding support for descriptions on variables. This will allow users to provide additional context about the purpose, usage, and expected values of workspace variables, improving readability, maintainability, and collaboration across teams.

Requirements

Add a Description field when creating or editing workspace variables.

Display the description alongside variable details in the workspace UI.

Support viewing and updating descriptions for existing variables.

Ensure descriptions are stored and retrieved through the corresponding backend APIs.

Maintain backward compatibility for variables that do not have descriptions.