feat: 医生端Web后台 + SignalR实时问诊

- 新增 doctor_web/ React前端 (dashboard/患者/问诊/报告/随访)
- 后端新增 doctor_endpoints (14个医生API) + ConsultationHub (SignalR)
- Flutter端 SignalR 替换轮询实现实时聊天

health_app/lib/providers/consultation_provider.dart

@@ -1,5 +1,7 @@
 import 'dart:async';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:signalr_netcore/signalr_client.dart';
+import '../core/api_client.dart' show baseUrl;
 import 'auth_provider.dart';
 
 class ConsultationMsg {
@@ -8,7 +10,6 @@ class ConsultationMsg {
   final String? senderName;
   final String content;
   final DateTime createdAt;
-  final List<String>? quickOptions;
 
   ConsultationMsg({
     required this.id,
@@ -16,7 +17,6 @@ class ConsultationMsg {
     this.senderName,
     required this.content,
     required this.createdAt,
-    this.quickOptions,
   });
 }
 
@@ -30,6 +30,7 @@ class ConsultationChatState {
   final List<ConsultationMsg> messages;
   final bool isLoading;
   final bool isSending;
+  final bool isConnected;
   final int quotaRemaining;
   final int quotaTotal;
 
@@ -43,6 +44,7 @@ class ConsultationChatState {
     this.messages = const [],
     this.isLoading = true,
     this.isSending = false,
+    this.isConnected = false,
     this.quotaRemaining = 3,
     this.quotaTotal = 3,
   });
@@ -57,6 +59,7 @@ class ConsultationChatState {
     List<ConsultationMsg>? messages,
     bool? isLoading,
     bool? isSending,
+    bool? isConnected,
     int? quotaRemaining,
     int? quotaTotal,
   }) =>
@@ -70,6 +73,7 @@ class ConsultationChatState {
         messages: messages ?? this.messages,
         isLoading: isLoading ?? this.isLoading,
         isSending: isSending ?? this.isSending,
+        isConnected: isConnected ?? this.isConnected,
         quotaRemaining: quotaRemaining ?? this.quotaRemaining,
         quotaTotal: quotaTotal ?? this.quotaTotal,
       );
@@ -80,7 +84,8 @@ final consultationChatProvider =
         ConsultationChatNotifier.new);
 
 class ConsultationChatNotifier extends Notifier<ConsultationChatState> {
-  Timer? _pollTimer;
+  HubConnection? _hub;
+  String get _hubUrl => '$baseUrl/hubs/consultation';
 
   @override
   ConsultationChatState build() => const ConsultationChatState();
@@ -127,12 +132,54 @@ class ConsultationChatNotifier extends Notifier<ConsultationChatState> {
         state = state.copyWith(consultationId: consultationId, isLoading: false);
       }
 
-      _startPolling();
+      // 建立 SignalR 连接
+      await _connectHub(consultationId);
     } catch (_) {
       state = state.copyWith(isLoading: false);
     }
   }
 
+  Future<void> _connectHub(String consultationId) async {
+    try {
+      _hub?.stop();
+      _hub = HubConnectionBuilder()
+          .withUrl(_hubUrl)
+          .withAutomaticReconnect()
+          .build();
+
+      // 注册消息接收
+      _hub!.on('ReceiveMessage', (args) {
+        if (args == null || args.isEmpty) return;
+        final data = args[0] as Map<String, dynamic>;
+        final msgConsultationId = data['consultationId']?.toString() ?? '';
+        if (msgConsultationId != consultationId) return;
+
+        final msg = ConsultationMsg(
+          id: data['id']?.toString() ?? DateTime.now().millisecondsSinceEpoch.toString(),
+          senderType: data['senderType']?.toString() ?? 'Ai',
+          senderName: data['senderName']?.toString(),
+          content: data['content']?.toString() ?? '',
+          createdAt: data['createdAt'] != null
+              ? DateTime.tryParse(data['createdAt'].toString()) ?? DateTime.now()
+              : DateTime.now(),
+        );
+
+        // 去重
+        final existingIds = state.messages.map((m) => m.id).toSet();
+        if (!existingIds.contains(msg.id)) {
+          state = state.copyWith(messages: [...state.messages, msg]);
+        }
+      });
+
+      await _hub!.start();
+      await _hub!.invoke('JoinConsultation', args: [consultationId]);
+      state = state.copyWith(isConnected: true);
+    } catch (_) {
+      // SignalR 连接失败，回退到轮询
+      _startPolling();
+    }
+  }
+
   Future<void> _loadDoctorInfo(String doctorId) async {
     try {
       final api = ref.read(apiClientProvider);
@@ -185,27 +232,37 @@ class ConsultationChatNotifier extends Notifier<ConsultationChatState> {
     );
 
     try {
-      final api = ref.read(apiClientProvider);
-      await api.post('/api/consultations/${state.consultationId}/messages', data: {'content': text});
-      state = state.copyWith(isSending: false);
-      _pollMessages();
+      // 优先通过 SignalR 发送
+      if (_hub != null && _hub!.state == HubConnectionState.Connected) {
+        await _hub!.invoke('SendMessage',
+            args: <Object>[state.consultationId!, 'User', '', text]);
+      } else {
+        // 回退到 HTTP
+        final api = ref.read(apiClientProvider);
+        await api.post('/api/consultations/${state.consultationId}/messages',
+            data: {'content': text});
+      }
     } catch (_) {
-      state = state.copyWith(isSending: false);
+      // 静默失败，消息已显示在本地
     }
+    state = state.copyWith(isSending: false);
   }
 
+  // ---- 轮询回退（SignalR 不可用时）----
+  Timer? _pollTimer;
+
   void _startPolling() {
     _pollTimer?.cancel();
-    _pollTimer = Timer.periodic(const Duration(seconds: 15), (_) => _pollMessages());
+    _pollTimer = Timer.periodic(const Duration(seconds: 5), (_) => _pollMessages());
   }
 
   Future<void> _pollMessages() async {
-    if (state.consultationId == null) return;
+    if (state.consultationId == null || state.isConnected) return;
     try {
       final api = ref.read(apiClientProvider);
       final lastId = state.messages.isNotEmpty ? state.messages.last.id : null;
       final params = <String, dynamic>{};
-      if (lastId != null && lastId.startsWith('greeting_') == false) {
+      if (lastId != null && !lastId.startsWith('greeting_')) {
         params['after'] = lastId;
       }
       final res = await api.get(
@@ -224,7 +281,8 @@ class ConsultationChatNotifier extends Notifier<ConsultationChatState> {
               senderType: map['senderType']?.toString() ?? 'User',
               senderName: map['senderName']?.toString(),
               content: map['content']?.toString() ?? '',
-              createdAt: DateTime.tryParse(map['createdAt']?.toString() ?? '') ?? DateTime.now(),
+              createdAt:
+                  DateTime.tryParse(map['createdAt']?.toString() ?? '') ?? DateTime.now(),
             );
           })
           .where((m) => !existingIds.contains(m.id))
@@ -236,7 +294,9 @@ class ConsultationChatNotifier extends Notifier<ConsultationChatState> {
     } catch (_) {}
   }
 
-  void stopPolling() {
+  void stop() {
+    _hub?.stop();
+    _hub = null;
     _pollTimer?.cancel();
     _pollTimer = null;
   }