Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

Python auth SDK supports upscoping on 403 insufficient scope errors. Typescript does not have this functionality yet. https://github.com/modelcontextprotocol/python-sdk/blob/main/src/mcp/client/auth.py

Describe the solution you'd like

Equivalent functionality to the 403 handling case here:
https://github.com/modelcontextprotocol/python-sdk/blob/main/src/mcp/client/auth.py

Describe alternatives you've considered

None.

Additional context
None