refactored lesson details, centralized logout logic, and added resume re-fetch

lib/state/app/infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart

@@ -60,10 +60,27 @@ abstract class LoadableHydratedBloc<
         error: event.error
     )));
 
+    on<Reset<TState>>((event, emit) => emit(const LoadableState(
+        isLoading: false,
+        data: null,
+        lastFetch: null,
+        reFetch: null,
+        error: null,
+    )));
+
     _repository = repository();
     fetch();
   }
 
+  /// Wipes this bloc's persisted state and resets the in-memory state to an
+  /// empty, non-loading shell. Intended for logout: callers must trigger a
+  /// fresh [fetch] (e.g. via [retry] or page-specific refresh) once the user
+  /// is authenticated again, otherwise the UI would stay blank.
+  Future<void> reset() async {
+    await clear();
+    add(Reset<TState>());
+  }
+
   TState? get innerState => state.data;
   TRepository get repo => _repository;
 

lib/state/app/infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart

@@ -14,3 +14,4 @@ class Error<TState> extends LoadableHydratedBlocEvent<TState> {
   Error(this.error);
 }
 class RefetchStarted<TState> extends LoadableHydratedBlocEvent<TState> {}
+class Reset<TState> extends LoadableHydratedBlocEvent<TState> {}