feat: surface read-only load errors

lib/providers/providers.dart

@@ -3,6 +3,8 @@ import 'dart:math' as math;
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:geolocator/geolocator.dart';
+import '../app/error_message.dart';
+import '../app/load_state.dart';
 import '../models/home_config.dart';
 import '../services/api_client.dart';
 import '../services/settings_service.dart';
@@ -694,50 +696,69 @@ class TasksNotifier extends Notifier<List<dynamic>> {
 
 // ─── Статистика ──────────────────────────────────────────────
 
-final statsProvider = NotifierProvider<StatsNotifier, Map<String, dynamic>>(
-  () => StatsNotifier(),
-);
+final statsProvider =
+    NotifierProvider<StatsNotifier, LoadState<Map<String, dynamic>>>(
+      () => StatsNotifier(),
+    );
 
-class StatsNotifier extends Notifier<Map<String, dynamic>> {
+class StatsNotifier extends Notifier<LoadState<Map<String, dynamic>>> {
   @override
-  Map<String, dynamic> build() => {};
+  LoadState<Map<String, dynamic>> build() =>
+      const LoadState.idle(<String, dynamic>{});
 
   Future<void> load({int days = 7}) async {
+    state = LoadState.loading(state.data);
     try {
       final api = ref.read(apiProvider);
       final res = await api.getStatsSummary(days: days);
       final data = res.data;
-      if (data is Map) {
-        state = Map<String, dynamic>.from(data);
+      if (data is! Map) {
+        throw FormatException('stats summary должен быть объектом');
       }
+
+      final stats = Map<String, dynamic>.from(data);
+      final groups = stats['groups'];
+      final hasGroups = groups is List && groups.isNotEmpty;
+      state = hasGroups ? LoadState.data(stats) : LoadState.empty(stats);
     } catch (e) {
-      debugPrint("Ошибка загрузки статистики: $e");
+      state = LoadState.error(state.data, describeLoadError(e));
     }
   }
 }
 
 // ─── Лог событий ─────────────────────────────────────────────
 
-final eventLogProvider = NotifierProvider<EventLogNotifier, List<dynamic>>(
-  () => EventLogNotifier(),
-);
+final eventLogProvider =
+    NotifierProvider<EventLogNotifier, LoadState<List<dynamic>>>(
+      () => EventLogNotifier(),
+    );
 
-class EventLogNotifier extends Notifier<List<dynamic>> {
+class EventLogNotifier extends Notifier<LoadState<List<dynamic>>> {
   @override
-  List<dynamic> build() => [];
+  LoadState<List<dynamic>> build() => const LoadState.idle(<dynamic>[]);
 
   Future<void> load({int limit = 100}) async {
+    state = LoadState.loading(state.data);
     try {
       final api = ref.read(apiProvider);
       final res = await api.getStatsLog(limit: limit);
       final data = res.data;
+      late final List<dynamic> events;
       if (data is List) {
-        state = data;
+        events = List<dynamic>.from(data);
       } else if (data is Map) {
-        state = data['data'] ?? data['events'] ?? data.values.toList();
+        final value = data['data'] ?? data['events'] ?? data.values.toList();
+        if (value is! List) {
+          throw FormatException('stats log должен быть списком событий');
+        }
+        events = List<dynamic>.from(value);
+      } else {
+        throw FormatException('stats log должен быть списком событий');
       }
+
+      state = events.isEmpty ? LoadState.empty(events) : LoadState.data(events);
     } catch (e) {
-      debugPrint("Ошибка загрузки логов: $e");
+      state = LoadState.error(state.data, describeLoadError(e));
     }
   }
 }