- Login_Test: split into 11 per-scenario @Test methods (8 invalid + 3 valid); fix Valid-before-Invalid ordering that left the browser logged in.
- Login.java: add granular helpers (attemptInvalidLogin, loginAndLogout, isLoggedOut); harden switchAccount() logout with a retry loop.
- Search/Cart/Profile/Registration/AddProduct: split each into per-scenario @Test methods sharing one browser (single @BeforeClass login); fix AddProduct double-login.
Co-Authored-By: Claude Opus 4.8 noreply@anthropic.com