Generate authorization server urls during API resolution.

[omgitsads]

Summary

Handle generation of the OAuth Authorization Server URL when we're parsing URLs for the underlying clients.

Why

As highlighted in #2046, we're not generating the OAuth Authorization Server URLs correctly.

This PR moves the generation into the APIHostResolver implementation and uses that in the OAuthHandler.

What changed

MCP impact

• No tool or API changes
• Tool schema or behavior changed
• New tool added

Prompts tested (tool changes only)

Security / limits

• No security or limits impact
• Auth / permissions considered
• Data exposure, filtering, or token/size limits considered

Tool renaming

• I am renaming tools as part of this PR (e.g. a part of a consolidation effort)
  • I have added the new tool aliases in deprecated_tool_aliases.go
• I am not renaming tools as part of this PR

Note: if you're renaming tools, you must add the tool aliases. For more information on how to do so, please refer to the official docs.

Lint & tests

• Linted locally with ./script/lint
• Tested locally with ./script/test

Docs

• Not needed
• Updated (README / docs / examples)

[Copilot]

Pull request overview

This pull request fixes the OAuth Authorization Server URL generation by moving it from the OAuth handler into the API host resolution logic. This addresses issue #2046 where the authorization server URLs were not being correctly generated for different GitHub host types (github.com, GHEC, and GHES).

Changes:

• Added AuthorizationServerURL method to the APIHostResolver interface and its implementations in pkg/utils/api.go
• Updated NewAuthHandler to accept context.Context and APIHostResolver parameters, using the resolver to get the authorization server URL instead of using a hardcoded constant
• Added comprehensive test coverage for the new authorization server URL resolution across different host types

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pkg/utils/api.go	Added AuthorizationServerURL method to interface and implementation; generates appropriate OAuth URLs for dotcom, GHEC, and GHES hosts
pkg/http/oauth/oauth.go	Modified NewAuthHandler to accept APIHostResolver and use it to dynamically resolve authorization server URLs; removed hardcoded DefaultAuthorizationServer constant
pkg/http/server.go	Updated call to NewAuthHandler to pass context and API host resolver
pkg/http/oauth/oauth_test.go	Updated all test calls with new parameters; added comprehensive test suite for authorization server URL resolution across host types
pkg/scopes/fetcher_test.go	Updated mock APIHostResolver implementation to include new AuthorizationServerURL method