feat(logging): add logging to ChatBloc

apps/lib/features/chat/presentation/bloc/chat_bloc.dart

@@ -4,6 +4,7 @@ import 'dart:typed_data';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:image_picker/image_picker.dart';
 import 'package:social_app/core/chat/chat_api.dart';
+import 'package:social_app/core/logging/logger.dart';
 import 'package:social_app/core/chat/agent_stage.dart';
 import 'package:social_app/core/chat/ag_ui_event.dart';
 import 'package:social_app/core/chat/ag_ui_service.dart';
@@ -107,6 +108,8 @@ class ChatState implements ChatOrchestratorState {
 }
 
 class ChatBloc extends Cubit<ChatState> implements ChatOrchestrator {
+  final Logger _logger = getLogger('features.chat.bloc');
+
   ChatBloc({
     AgUiService? service,
     required ChatApi chatApi,

apps/lib/features/chat/presentation/bloc/chat_bloc_send.dart

@@ -4,6 +4,14 @@ part of 'chat_bloc.dart';
 
 extension _ChatBlocSend on ChatBloc {
   Future<void> _sendMessage(String content, {List<XFile>? images}) async {
+    _logger.info(
+      message: 'Sending chat message',
+      extra: {
+        'message_length': content.length,
+        'attachments_count': images?.length ?? 0,
+      },
+    );
+
     final epoch = _sessionEpoch;
     final assistantBaselineAtSend = chatBlocLatestAssistantTimestamp(
       state.items,
@@ -57,11 +65,21 @@ extension _ChatBlocSend on ChatBloc {
       if (epoch != _sessionEpoch) {
         return;
       }
+      _logger.info(
+        message: 'Chat message sent successfully',
+        extra: {'message_id': messageId},
+      );
       _syncUploadedAttachments(
         messageId: messageId,
         uploadedAttachments: sendResult.uploadedAttachments,
       );
-    } catch (error) {
+    } catch (error, stackTrace) {
+      _logger.error(
+        message: 'Failed to send chat message',
+        error: error,
+        stackTrace: stackTrace,
+        extra: {'message': content},
+      );
       if (epoch != _sessionEpoch) {
         return;
       }