This pull request introduces support for "pod"-specific App Store endpoints, enhancing how requests are routed and authenticated. The main changes involve fetching the correct authentication endpoint dynamically, propagating the "pod" information through the login flow, and updating all relevant requests to use the pod-specific host if available. Comprehensive tests have been added for these new behaviors.

Pod-aware endpoint support:

• Added a new Bag method to the AppStore interface and its implementation, which fetches endpoint definitions (including the authentication endpoint) from the App Store "bag" service. (pkg/appstore/appstore.go, pkg/appstore/appstore_bag.go, [1] [2]
• Updated the login flow to use the authentication endpoint from the bag and to extract and store the "pod" value from login responses in the Account struct. (cmd/auth.go, pkg/appstore/account.go, pkg/appstore/appstore_login.go, [1] [2] [3] [4] [5] [6] [7] [8] [9]

Pod-specific request routing:

• Modified download, version metadata, and list versions requests to use a pod-specific host if the Account.Pod field is set, ensuring requests are routed correctly for users assigned to a particular pod. (pkg/appstore/appstore_download.go, pkg/appstore/appstore_get_version_metadata.go, pkg/appstore/appstore_list_versions.go, [1] [2] [3] [4]

Testing improvements:

• Added new tests for the Bag method, as well as tests to verify that pod-specific hosts are used in download, get version metadata, and list versions requests. (pkg/appstore/appstore_bag_test.go, pkg/appstore/appstore_download_test.go, pkg/appstore/appstore_get_version_metadata_test.go, pkg/appstore/appstore_list_versions_test.go, [1] [2] [3] [4]
• Enhanced login tests to check for correct handling of the "pod" value in the Account struct and in request routing. (pkg/appstore/appstore_login_test.go, [1] [2] [3] [4] [5]