* fix: update browser cache handling in website proxy service
- Adjusted cache time condition to allow for negative values, introducing a no-cache option.
- Updated TypeScript interface to specify browser cache options as 'enable', 'disable', or 'noModify' for better clarity.
* refactor: clean up imports and enhance browser cache comments in website proxy service
- Removed unused import statements for better code clarity.
- Added detailed comments to clarify the behavior of the cache time settings in the OperateProxy function.