Adds sampling and list roots callbacks to the ClientSession, allowing the client to handle requests from the server.
Co-authored-by: TerminalMan <84923604+SecretiveShell@users.noreply.github.com>
Co-authored-by: David Soria Parra <davidsp@anthropic.com>
We currently return a generic instance of RequestContext without
a specialization on the Session type. This makes it impossible
for servers to typesafe call `list_roots()` and other methods.
We now return a specific instance of `RequestContext[ServerSession]`
We will be a bit more low level and expect callees to import mcp.types
instead of relying in re-exported types. This makes usage more explicit
and avoids potential collisions in mcp.server.
