Add MainHUD gameplay UI, net handshake updates, and server maintenance mode.

Introduce UiManager/MainHUD prefab flow, strengthen GameNet/WsClient, and add AIServer maintenance endpoint support.

Co-authored-by: Cursor <cursoragent@cursor.com>

AIClient/Assets/HotUpdate/Scripts/Net/GameNet.cs

@@ -6,7 +6,7 @@ using UnityEngine;
 namespace HotUpdate.Net
 {
     /// <summary>
-    /// 登录 → WS 连接编排。
+    /// 登录 → WS 连接编排（含指数退避重连与维护公告）。
     /// </summary>
     public sealed class GameNet : MonoBehaviour
     {
@@ -21,9 +21,14 @@ namespace HotUpdate.Net
         public event Action OnWsReady;
         public event Action<string> OnStatus;
         public event Action<string> OnWsMessage;
+        public event Action<string> OnWsDisconnected;
+        public event Action<int> OnReconnecting;
+        public event Action<string> OnMaintenance;
 
         BootContext _boot;
         bool _started;
+        bool _maintenance;
+        bool _everConnected;
 
         public void Bind(BootContext boot)
         {
@@ -35,7 +40,6 @@ namespace HotUpdate.Net
 
             if (!string.IsNullOrEmpty(_boot.WsUrlTemplate))
             {
-                // 旧模板只有 pid 时补上 token
                 var tpl = _boot.WsUrlTemplate;
                 if (!tpl.Contains("{token}"))
                 {
@@ -54,11 +58,37 @@ namespace HotUpdate.Net
             StartCoroutine(RunGuestFlow());
         }
 
+        /// <summary>UI「立即重连」：重置退避并马上再连。</summary>
+        public void RequestReconnect()
+        {
+            if (_maintenance || Session == null || !Session.IsValid) return;
+            SetStatus("手动重连…");
+            if (Socket != null)
+            {
+                Socket.AutoReconnect = true;
+                Socket.ForceReconnect();
+            }
+            else
+                StartCoroutine(ConnectWs());
+        }
+
+        public void NotifyMaintenance(string message)
+        {
+            if (_maintenance) return;
+            _maintenance = true;
+            if (Socket != null)
+            {
+                Socket.AutoReconnect = false;
+                Socket.Close();
+            }
+            SetStatus("maintenance");
+            OnMaintenance?.Invoke(message ?? "服务器维护中");
+        }
+
         IEnumerator RunGuestFlow()
         {
             SetStatus("auth…");
             var deviceId = DeviceId.GetOrCreate();
-            // 服务器要求 username/password；编辑器自动账号
             var username = $"guest_{deviceId}";
             var password = $"pw_{deviceId}";
 
@@ -89,6 +119,7 @@ namespace HotUpdate.Net
 
         IEnumerator ConnectWs()
         {
+            if (_maintenance) yield break;
             if (Session == null || !Session.IsValid)
             {
                 SetStatus("no session");
@@ -99,14 +130,13 @@ namespace HotUpdate.Net
             Socket?.Dispose();
             Socket = new WsClient();
             Socket.AutoReconnect = true;
-            Socket.OnConnected += () =>
+            Socket.OnConnected += HandleConnected;
+            Socket.OnDisconnected += HandleDisconnected;
+            Socket.OnReconnecting += attempt =>
             {
-                SetStatus("ws connected");
-                OnWsReady?.Invoke();
-                // 应用层握手（服务端当前可无响应，保留扩展）
-                Socket.SendText($"{{\"op\":\"hello\",\"proto\":1,\"app\":\"{_boot?.AppVersion}\",\"res\":\"{_boot?.ResVersion}\",\"pid\":{Session.Pid}}}");
+                SetStatus($"ws reconnecting #{attempt}");
+                OnReconnecting?.Invoke(attempt);
             };
-            Socket.OnDisconnected += reason => SetStatus($"ws down: {reason}");
             Socket.OnMessage += msg =>
             {
                 Debug.Log($"[GameNet] << {msg}");
@@ -116,7 +146,6 @@ namespace HotUpdate.Net
             var url = Session.BuildWsUrl(WsUrlTemplate);
             Socket.Connect(url);
 
-            // 等待最多 15s
             float t = 0f;
             while (t < 15f && Socket.State != WsState.Connected && Socket.State != WsState.Disconnected)
             {
@@ -132,6 +161,28 @@ namespace HotUpdate.Net
                 SetStatus($"ws state={Socket.State}");
         }
 
+        void HandleConnected()
+        {
+            if (_maintenance) return;
+            SetStatus(_everConnected ? "ws reconnected" : "ws connected");
+            _everConnected = true;
+            SendHello();
+            OnWsReady?.Invoke();
+        }
+
+        void HandleDisconnected(string reason)
+        {
+            SetStatus($"ws down: {reason}");
+            OnWsDisconnected?.Invoke(reason ?? "closed");
+        }
+
+        void SendHello()
+        {
+            if (Socket == null || Session == null) return;
+            Socket.SendText(
+                $"{{\"op\":\"hello\",\"proto\":1,\"app\":\"{_boot?.AppVersion}\",\"res\":\"{_boot?.ResVersion}\",\"pid\":{Session.Pid}}}");
+        }
+
         void Update()
         {
             Socket?.Tick();