feat(session): centralize session teardown and refresh

Add SessionLifecycleService to reset user-scoped cubits, analytics, socket id and account-scoped preferences on logout, 401 or account deletion. Run the same refresh after every successful auth path, including registration v1/v2, and ignore 401 responses from stale tokens so an old request cannot terminate the new user's session.

Refs: #1113

lib/features/settings/presentation/pages/settings_screen.dart

@@ -698,7 +698,6 @@ class _DeleteAccountBottomSheet extends State<DeleteAccountBottomSheet> {
             onPressed: () async {
               final result = await widget.cubit.deleteAccount();
               if (result == true) {
-                AppRouter.navigatorKey.currentContext?.go('/auth-screen');
                 return;
               }
               AppRouter.navigatorKey.currentContext?.pop();