Access access token from outside auth package

[ayumitamai97]

Is your feature request related to a problem? Please describe.

After authorization is completed, the access token is added to the current context, but it's not accessible from outside the auth package.
It is causing a problem when an MCP tool requires the access token to get the currently logged in user's information.

Describe the solution you'd like

1. Export tokenInfoKey so that an MCP tool can retrieve the token so that it can be used from outside the package.
2. Add AccessToken field to TokenInfo struct.

Describe alternatives you've considered

Defining access_token as MCP parameter. However this doesn't work because MCP clients does not always append access_token to the MCP tool call as parameter.

Additional context

I'm trying out the auth package with the version v0.2.1-0.20250812214950-6e03217c831b.

[jba]

#292 will fix that.

[ayumitamai97]

Cool! Thank you for your response.