simplify: dedupe boilerplate and remove dead code across all layers

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

@@ -123,23 +123,28 @@ abstract class LoadableHydratedBloc<
     fetch();
   }
 
+  /// Maps [e] through the shared error mapper and emits it as an [Error] event.
+  /// Does not guard [isClosed] — callers decide whether a late error still
+  /// applies.
+  void addLoadingError(Object e) => add(
+    Error(
+      LoadingError(
+        message: errorToUserMessage(e),
+        technicalDetails: errorToTechnicalDetails(e),
+        allowRetry: errorAllowsRetry(e),
+      ),
+    ),
+  );
+
   void fetch() {
     log('Fetching data for ${TState.toString()}');
     gatherData()
-        .catchError((e) {
+        .catchError((Object e) {
           log('Error while fetching ${TState.toString()}: ${e.toString()}');
           // The bloc may have been closed before this async error landed;
           // adding to a closed bloc throws, so swallow that case.
           if (isClosed) return;
-          add(
-            Error(
-              LoadingError(
-                message: errorToUserMessage(e),
-                technicalDetails: errorToTechnicalDetails(e),
-                allowRetry: errorAllowsRetry(e),
-              ),
-            ),
-          );
+          addLoadingError(e);
         })
         .then((value) {
           log('Fetch for ${TState.toString()} completed!');