Fix critical SignalR connection recovery issue

This commit fixes a critical bug where the SignalR connection would not recover after the automatic reconnect mechanism exhausted its retry attempts. This caused services using SignalRHostedService to permanently lose connectivity and require manual restart.

Changes:
- Added automatic reconnection logic in the Closed event handler
- When connection closes unexpectedly, it now triggers ExecuteStartUp() which uses the Polly retry policy with infinite retries
- Added semaphore lock to prevent multiple simultaneous reconnection attempts
- Added isShuttingDown flag to prevent reconnection during graceful shutdown
- Improved logging for connection lifecycle events

This resolves the issue where services would crash with WebSocketException and require manual restart when network connectivity was temporarily lost.

Version bumped to 2.2.3

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: spewu

ProReception.DistributionServerInfrastructure/HostedServices/SignalRHostedService.cs

@@ -25,9 +25,11 @@ public abstract class SignalRHostedService<T>(
     : IHostedService
 {
     private readonly CancellationTokenSource stoppingCts = new();
+    private readonly SemaphoreSlim reconnectLock = new(1, 1);
 
     private Task? startUpTask;
     private HubConnection? hubConnection;
+    private bool isShuttingDown;
 
     protected abstract string HubPath { get; }
 
@@ -51,6 +53,9 @@ public async Task StopAsync(CancellationToken cancellationToken)
     {
         logger.LogInformation($"Stopping {typeof(T).Name}...");
 
+        // Set flag to prevent reconnection attempts during shutdown
+        isShuttingDown = true;
+
         // Stop called without start
         if (startUpTask == null)
         {
@@ -167,11 +172,44 @@ private async Task LoginAndCreateSignalRConnection(CancellationToken cancellatio
                 return Task.CompletedTask;
             };
 
-            hubConnection.Closed += error =>
+            hubConnection.Closed += async error =>
             {
-                // Do not call StopAsync or recursively restart; rely on automatic reconnect and outer retry/startup logic
-                logger.LogInformation(error, "SignalR connection closed. Waiting for background retry logic...");
-                return Task.CompletedTask;
+                if (isShuttingDown)
+                {
+                    logger.LogInformation("SignalR connection closed during shutdown, not reconnecting");
+                    return;
+                }
+
+                logger.LogWarning(error, "SignalR connection closed unexpectedly. Attempting to reconnect...");
+
+                // Use semaphore to prevent multiple simultaneous reconnection attempts
+                if (await reconnectLock.WaitAsync(0))
+                {
+                    try
+                    {
+                        // Dispose the old connection
+                        if (hubConnection != null)
+                        {
+                            await hubConnection.DisposeAsync();
+                            hubConnection = null;
+                        }
+
+                        // Restart the connection with retry logic
+                        await ExecuteStartUp(stoppingCts.Token);
+                    }
+                    catch (Exception ex)
+                    {
+                        logger.LogError(ex, "Failed to reconnect SignalR after connection closed. Will be retried by Polly policy");
+                    }
+                    finally
+                    {
+                        reconnectLock.Release();
+                    }
+                }
+                else
+                {
+                    logger.LogInformation("Reconnection already in progress, skipping duplicate attempt");
+                }
             };
 
             await hubConnection.StartAsync(cancellationToken);

version.props

@@ -1,5 +1,5 @@
 <Project>
     <PropertyGroup>
-        <Version>2.2.2</Version>
+        <Version>2.2.3</Version>
     </PropertyGroup>
 </Project>