fix(discovery): 终态心跳写入加 2s 超时并脱离同步上下文

GameFrameX.Discovery/Discovery/DiscoveryRegistry.cs

@@ -355,11 +355,7 @@ public void Dispose()
         try
         {
             _loopCancellation.Cancel();
-            WriteStoppedAsync().GetAwaiter().GetResult();
-        }
-        catch (Exception)
-        {
-            // 尽力而为：进程退出路径上数据库不可达时无法补写终态，交给 TTL 兜底清除。
+            WriteTerminalHeartbeatSafely();
         }
         finally
         {
@@ -470,13 +466,32 @@ private static async Task WaitLoopAsync(Task loopTask)
     /// <param name="eventArguments">事件参数 / The event arguments</param>
     private void OnProcessExit(object sender, EventArgs eventArguments)
     {
-        try
-        {
-            WriteStoppedAsync().GetAwaiter().GetResult();
-        }
-        catch (Exception)
+        WriteTerminalHeartbeatSafely();
+    }
+
+    /// <summary>
+    /// 终态心跳的同步尽力写入：2 秒超时 + Task.Run 脱离可能的 SynchronizationContext，
+    /// 避免存在同步上下文时死锁；失败/超时记日志不阻塞退出（TTL 兜底清除）。
+    /// </summary>
+    /// <remarks>
+    /// Best-effort synchronous write of the terminal heartbeat: a 2-second timeout and
+    /// Task.Run to escape any SynchronizationContext (deadlock guard); failures and
+    /// timeouts are logged without blocking exit (TTL cleanup is the fallback).
+    /// </remarks>
+    private void WriteTerminalHeartbeatSafely()
+    {
+        using (var cancellation = new CancellationTokenSource(TimeSpan.FromSeconds(2)))
         {
-            // 进程退出路径上数据库不可达时无法补写终态，交给 TTL 兜底清除。
+            try
+            {
+                Task.Run(() => WriteStoppedAsync(), cancellation.Token).GetAwaiter().GetResult();
+            }
+            catch (Exception exception)
+            {
+                // 尽力而为：进程退出路径上数据库不可达/超时时无法补写终态，交给 TTL 兜底清除。
+                // Localization: Discovery.Registry.TerminalHeartbeatFailed - [DiscoveryRegistry] 终态心跳写入失败（超时 2s 内未完成），交给 TTL 兜底清除
+                LogHelper.Error(exception, LocalizationService.GetString(Localization.Keys.Discovery.Registry.TerminalHeartbeatFailed));
+            }
         }
     }
 

GameFrameX.Localization/Keys.Discovery.cs

@@ -235,6 +235,15 @@ public static class Registry
             /// </remarks>
             public const string TtlCleanupFailed = "Discovery.Registry.TtlCleanupFailed";
 
+            /// <summary>
+            /// [DiscoveryRegistry] 终态心跳写入失败（超时 2s 内未完成），交给 TTL 兜底清除
+            /// </summary>
+            /// <remarks>
+            /// 键名: Discovery.Registry.TerminalHeartbeatFailed
+            /// 用途: Dispose/ProcessExit 终态心跳尽力写入失败或超时时的错误日志
+            /// </remarks>
+            public const string TerminalHeartbeatFailed = "Discovery.Registry.TerminalHeartbeatFailed";
+
             /// <summary>
             /// 附加广播端点未被发布：服务进程类型 '{0}' 不是本进程心跳承载的首选类型 '{1}'（心跳文档单 Role 模型，非首选类型不跨进程可达）
             /// </summary>

GameFrameX.Localization/Localization/Messages/Resources.resx

@@ -1984,6 +1984,10 @@
     <value>[AdvertiseEndpointEnvironment] egress address detection failed; falling back to the machine name {0} as the advertise host. Set {1} explicitly when cross-process routing is required.</value>
   </data>
 
+
+  <data name="Discovery.Registry.TerminalHeartbeatFailed" xml:space="preserve">
+    <value>[DiscoveryRegistry] terminal heartbeat write failed (not completed within the 2s timeout); leaving it to TTL cleanup</value>
+  </data>
   <data name="Discovery.Registry.HeartbeatUpsertFailed" xml:space="preserve">
     <value>[DiscoveryRegistry] heartbeat upsert failed for instance {0}; will retry next interval</value>
   </data>

GameFrameX.Localization/Localization/Messages/Resources.zh-CN.resx

@@ -1978,6 +1978,10 @@
     <value>[AdvertiseEndpointEnvironment] 出口地址探测失败；回退使用机器名 {0} 作为广播主机。需要跨进程路由时请显式设置 {1}</value>
   </data>
 
+
+  <data name="Discovery.Registry.TerminalHeartbeatFailed" xml:space="preserve">
+    <value>[DiscoveryRegistry] 终态心跳写入失败（超时 2s 内未完成），交给 TTL 兜底清除</value>
+  </data>
   <data name="Discovery.Registry.HeartbeatUpsertFailed" xml:space="preserve">
     <value>[DiscoveryRegistry] 实例 {0} 心跳写入失败；将在下个间隔重试</value>
   </data>