refactored data providers with centralized cache resolution, unified UI using custom dialogs and bottom sheets, and enhanced network error handling for Dio and TLS errors

lib/api/request_cache.dart

@@ -4,6 +4,7 @@ import 'dart:convert';
 import 'package:localstore/localstore.dart';
 
 import 'api_response.dart';
+import 'errors/parse_exception.dart';
 
 abstract class RequestCache<T extends ApiResponse?> {
   static const int cacheNothing = 0;
@@ -81,10 +82,8 @@ abstract class RequestCache<T extends ApiResponse?> {
 
 }
 
-/// Concrete [RequestCache] that delegates the two overrides to functions
-/// passed in the constructor. Used to collapse the dozens of one-class-per-
-/// endpoint cache files that all just forward to `<Endpoint>().run()` and
-/// `<Response>.fromJson(jsonDecode(...))`.
+/// Concrete [RequestCache] that takes the two overrides as constructor
+/// callbacks instead of requiring a subclass per endpoint.
 class SimpleCache<T extends ApiResponse?> extends RequestCache<T> {
   final Future<T> Function() _loader;
   final T Function(Map<String, dynamic> json) _fromJson;
@@ -115,3 +114,30 @@ class SimpleCache<T extends ApiResponse?> extends RequestCache<T> {
   @override
   T onLocalData(String json) => _fromJson(jsonDecode(json) as Map<String, dynamic>);
 }
+
+/// Captures the latest cache payload (cached or network) and rethrows the
+/// captured network error if no payload arrived. Collapses the
+/// `latest`/`capturedError`/`await ready` boilerplate that DataProviders
+/// otherwise repeat per endpoint.
+Future<T> resolveFromCache<T extends ApiResponse?>(
+  RequestCache<T> Function(void Function(T) onUpdate, void Function(Exception) onError) build, {
+  void Function(Object)? onError,
+  String? operationName,
+}) async {
+  T? latest;
+  Object? capturedError;
+  final cache = build(
+    (data) => latest = data,
+    (e) {
+      capturedError = e;
+      onError?.call(e);
+    },
+  );
+  await cache.ready;
+  if (latest != null) return latest as T;
+  final err = capturedError;
+  if (err != null) throw err;
+  throw ParseException(
+    technicalDetails: operationName != null ? 'No data and no error from $operationName' : null,
+  );
+}