Extracted complex logic from `AuthService.login` into private helper methods (`_validateAndNormalizeLoginInputs`, `_checkAccessControl`, `_updateGlobalState`, `_updateSavedProfiles`, `_initiatePostLogin`) to improve readability and maintainability.
Moved `SimpleEventEmitter` to `js/utils/simpleEventEmitter.js` and auth constants/normalization helpers to `js/services/authUtils.js` to reduce file size and coupling.
Co-authored-by: PR0M3TH3AN <[email protected]>