feat: Added OAuth Auth Code Flow for GH Codespaces

[christian-kreuzberger-dtx]

The problem is that on GH Codespaces, localhost is not an address that we can use, as this runs somewhere in the cloud.
Luckily, there is a fix for this ^^

Proof:

[MrManny]

Spicy!

[Copilot]

Pull Request Overview

This PR adds GitHub Codespaces support for OAuth authentication by automatically detecting when the MCP server is running in Codespaces and using the forwarded URL instead of localhost for OAuth redirects.

Key changes:

• Created utility functions to detect GitHub Codespaces environment and generate forwarded URLs
• Updated OAuth redirect server to use forwarded URLs when running in Codespaces
• Added comprehensive test coverage for the new environment detection utilities

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/utils/environment-detection.ts	New utility module providing Codespaces detection and forwarded URL generation
src/utils/environment-detection.test.ts	Comprehensive test suite for environment detection utilities
src/authentication/dynatrace-oauth-auth-code-flow.ts	Updated OAuth redirect server to use forwarded URLs in Codespaces
src/authentication/dynatrace-oauth-auth-code-flow.test.ts	Added tests verifying OAuth redirect behavior in Codespaces and localhost
CHANGELOG.md	Documented the OAuth callback URL fix for GitHub Codespaces

Comments suppressed due to low confidence (1)

src/authentication/dynatrace-oauth-auth-code-flow.ts:184

• The server binds to 'localhost' which will not work in GitHub Codespaces. When running in Codespaces, the server should bind to '0.0.0.0' to accept forwarded connections from the Codespaces proxy. Consider conditionally setting the hostname based on whether running in Codespaces: server.listen(port, forwardedUrl ? '0.0.0.0' : 'localhost', () => {

    server.listen(port, 'localhost', () => {