Goal: Modernize the Environment Settings feature and strengthen UX + test coverage.
Requirements
- Convert / rewrite the Environment Settings feature using SwiftUI.
- Improve UI, accessibility, and visual polish on the main screen and environment screen.
- Remove the Endpoints section (no longer needed).
- Display the selected OAuth environment and whether the feature is enabled on the main screen.
- Ensure the project builds with the latest Xcode without warnings.
- Add unit tests to cover key behavior.