refactor(ax): AX compliance sweep — comments, error handling, test names
- Fix window/service.go: replace 3 fmt.Errorf calls with coreerr.E() (removes implicit fmt dependency)
- Add usage-example comments to all bare Register() functions across 10 packages
- Remove redundant prose comments (Options/Service/Register/OnStartup/HandleIPCEvents boilerplate)
- Add Result-type comments to message types in contextmenu, keybinding, notification packages
- Fix test naming to TestFilename_Function_{Good,Bad,Ugly} pattern in display_test, window_test, persistence_test, service_screen_test
- Convert New() and CreateWindowOptions doc comments to usage-example style
Co-Authored-By: Virgil <virgil@lethean.io>
13a493f57d