Clean up LLM digest provider errors

lib/features/ai_digest/application/llm_digest_orchestrator.dart

@@ -2,6 +2,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:relationship_saver/app/data/relationship_repository.dart';
 import 'package:relationship_saver/app/state/local_data_state.dart';
 import 'package:relationship_saver/core/llm/llm_config.dart';
+import 'package:relationship_saver/core/llm/llm_service.dart';
 import 'package:relationship_saver/features/ai_digest/application/ai_digest_notifier.dart';
 import 'package:relationship_saver/features/ai_digest/application/ai_digest_response_parser.dart';
 import 'package:relationship_saver/features/ai_digest/application/anonymized_llm_context_builder.dart';
@@ -185,11 +186,12 @@ class LlmDigestOrchestrator {
         createdDraftCount: parsed.drafts.length,
       );
     } catch (error) {
-      await _markFailure('$error');
+      final String reason = _digestFailureReason(error);
+      await _markFailure(reason);
       return LlmDigestRunResult(
         started: true,
         completed: false,
-        reason: '$error',
+        reason: reason,
       );
     }
   }
@@ -232,6 +234,13 @@ class LlmDigestOrchestrator {
   }
 }
 
+String _digestFailureReason(Object error) {
+  if (error is LlmProviderException) {
+    return error.message;
+  }
+  return '$error';
+}
+
 const String _systemPrompt = '''
 You create private relationship-maintenance digest suggestions.
 The input contains pseudonymous people only. Never ask for or invent names.

test/features/ai_digest/llm_digest_orchestrator_test.dart

@@ -4,6 +4,8 @@ import 'package:relationship_saver/app/data/relationship_repository.dart';
 import 'package:relationship_saver/app/data/storage/local_data_store_in_memory.dart';
 import 'package:relationship_saver/app/data/storage/local_data_store_provider.dart';
 import 'package:relationship_saver/app/state/local_data_state.dart';
+import 'package:relationship_saver/core/llm/llm_config.dart';
+import 'package:relationship_saver/core/llm/llm_service.dart';
 import 'package:relationship_saver/features/ai_digest/application/ai_digest_notifier.dart';
 import 'package:relationship_saver/features/ai_digest/application/llm_digest_environment.dart';
 import 'package:relationship_saver/features/ai_digest/application/llm_digest_orchestrator.dart';
@@ -117,10 +119,45 @@ void main() {
     expect(result.started, isFalse);
     expect(textClient.calls, 0);
   });
+
+  test('manual digest reports provider rate limits without Dio noise', () async {
+    final ThrowingTextClient textClient = ThrowingTextClient(
+      error: const LlmProviderException(
+        provider: LlmProvider.openai,
+        statusCode: 429,
+        message:
+            'OpenAI rejected the digest request with 429 rate limiting or quota pressure.',
+      ),
+    );
+    final ProviderContainer container = _createContainer(
+      textClient: textClient,
+      notifier: FakeNotifier(),
+    );
+    addTearDown(container.dispose);
+
+    await container.read(localRepositoryProvider.future);
+    await container
+        .read(localRepositoryProvider.notifier)
+        .addPerson(
+          name: 'Taylor Quinn',
+          relationship: 'Friend',
+          notes: '',
+          tags: const <String>['tea'],
+        );
+
+    final LlmDigestRunResult result = await container
+        .read(llmDigestOrchestratorProvider)
+        .runManualDigest();
+
+    expect(result.started, isTrue);
+    expect(result.completed, isFalse);
+    expect(result.reason, contains('429 rate limiting'));
+    expect(result.reason, isNot(contains('DioException')));
+  });
 }
 
 ProviderContainer _createContainer({
-  required FakeTextClient textClient,
+  required LlmDigestTextClient textClient,
   required FakeNotifier notifier,
   LlmDigestEnvironment environment = const FakeEnvironment(),
 }) {
@@ -158,6 +195,20 @@ class FakeTextClient implements LlmDigestTextClient {
   }
 }
 
+class ThrowingTextClient implements LlmDigestTextClient {
+  const ThrowingTextClient({required this.error});
+
+  final Object error;
+
+  @override
+  Future<String> complete({
+    required String systemPrompt,
+    required String userPrompt,
+  }) async {
+    throw error;
+  }
+}
+
 class FakeNotifier implements AiDigestNotifier {
   int? lastCount;