Fix IPC framing, add global pipe name, and auto-reconnect tests

apps/KronaStaffTerminal.Tests/Mocks/MockFingerprintScanner.cs

@@ -15,6 +15,7 @@ public sealed class MockFingerprintScanner : IFingerprintScanner
     public IReadOnlyList<ScannerDeviceInfo> DiscoveredDevices => _devices;
     public bool IsConnected => State == ScannerState.Connected || State == ScannerState.Busy;
     public int SkippedTemplateCount { get; set; } = 0;
+    public int ConnectCallCount { get; private set; } = 0;
 
     public event Action<int, int>? FingerRecognized;
     public event Action<int>? RegistrationProgress;
@@ -47,6 +48,7 @@ public sealed class MockFingerprintScanner : IFingerprintScanner
 
     public void Connect(int readerIndex, IEnumerable<(int FingerprintId, string Template)> templates)
     {
+        ConnectCallCount++;
         if (_devices.Count == 0)
         {
             State = ScannerState.DriverError;

apps/KronaStaffTerminal.Tests/ScannerRecoveryTests.cs

@@ -73,4 +73,45 @@ public class ScannerRecoveryTests
         Assert.Null(error);
         Assert.False(rehashNeeded);
     }
+    
+    [Fact]
+    public async Task Scanner_AutoReconnectLogic_CallsConnectSuccessfully()
+    {
+        using var scanner = new MockFingerprintScanner();
+        scanner.Connect(0, Array.Empty<(int, string)>());
+        Assert.Equal(1, scanner.ConnectCallCount);
+
+        var reconnectTcs = new TaskCompletionSource();
+        scanner.ConnectionLost += async () =>
+        {
+            // Simulate typical application retry loop
+            int retries = 0;
+            while (retries < 5)
+            {
+                await Task.Delay(10);
+                try
+                {
+                    scanner.Connect(0, Array.Empty<(int, string)>());
+                    if (scanner.IsConnected)
+                    {
+                        reconnectTcs.TrySetResult();
+                        return;
+                    }
+                }
+                catch { }
+                retries++;
+            }
+            reconnectTcs.TrySetException(new Exception("Failed to reconnect"));
+        };
+
+        scanner.SimulateDisconnect();
+        // Emulate the hardware coming back after a short delay
+        await Task.Delay(20);
+        scanner.AddVirtualDevice(0, "SLK20R", "SERIAL"); // ensure device is discoverable if it was cleared
+
+        await reconnectTcs.Task;
+        
+        Assert.True(scanner.ConnectCallCount > 1);
+        Assert.Equal(ScannerState.Connected, scanner.State);
+    }
 }

apps/KronaStaffTerminal/Services/TerminalIpc.cs

@@ -37,6 +37,7 @@ public sealed class IpcServiceStatus
 public static class TerminalIpcConstants
 {
     public const string PipeName = "KronaStaffTerminalPipe";
+    public const string PipeServerName = ".";
 }
 
 public sealed class TerminalIpcClient
@@ -74,20 +75,36 @@ public sealed class TerminalIpcClient
     {
         try
         {
-            await using var pipe = new NamedPipeClientStream(".", TerminalIpcConstants.PipeName, PipeDirection.InOut, PipeOptions.Asynchronous);
+            await using var pipe = new NamedPipeClientStream(TerminalIpcConstants.PipeServerName, TerminalIpcConstants.PipeName, PipeDirection.InOut, PipeOptions.Asynchronous);
             using var timeoutCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
             timeoutCts.CancelAfter(TimeSpan.FromSeconds(2));
 
             await pipe.ConnectAsync(timeoutCts.Token);
 
             var request = new IpcRequest { Command = command, Payload = payload };
-            var json = JsonSerializer.Serialize(request) + "\n";
+            var json = JsonSerializer.Serialize(request);
             var bytes = Encoding.UTF8.GetBytes(json);
+            var lengthPrefix = BitConverter.GetBytes(bytes.Length);
+            await pipe.WriteAsync(lengthPrefix, cancellationToken);
             await pipe.WriteAsync(bytes, cancellationToken);
             await pipe.FlushAsync(cancellationToken);
 
-            using var reader = new StreamReader(pipe, Encoding.UTF8);
-            var responseJson = await reader.ReadLineAsync(cancellationToken);
+            var respLenBytes = new byte[4];
+            var read = await pipe.ReadAsync(respLenBytes, cancellationToken);
+            if (read < 4) return null;
+            var respLen = BitConverter.ToInt32(respLenBytes);
+            if (respLen is <= 0 or > 10 * 1024 * 1024) return null;
+
+            var respBytes = new byte[respLen];
+            var totalRead = 0;
+            while (totalRead < respLen)
+            {
+                var r = await pipe.ReadAsync(respBytes.AsMemory(totalRead), cancellationToken);
+                if (r == 0) return null;
+                totalRead += r;
+            }
+
+            var responseJson = Encoding.UTF8.GetString(respBytes);
             if (string.IsNullOrWhiteSpace(responseJson)) return null;
 
             return JsonSerializer.Deserialize<IpcResponse>(responseJson);
@@ -152,8 +169,22 @@ public sealed class TerminalIpcServer : IDisposable
         {
             try
             {
-                using var reader = new StreamReader(stream, Encoding.UTF8, leaveOpen: true);
-                var line = await reader.ReadLineAsync(token);
+                var reqLenBytes = new byte[4];
+                var read = await stream.ReadAsync(reqLenBytes, token);
+                if (read < 4) return;
+                var reqLen = BitConverter.ToInt32(reqLenBytes);
+                if (reqLen is <= 0 or > 10 * 1024 * 1024) return;
+
+                var reqBytes = new byte[reqLen];
+                var totalRead = 0;
+                while (totalRead < reqLen)
+                {
+                    var r = await stream.ReadAsync(reqBytes.AsMemory(totalRead), token);
+                    if (r == 0) return;
+                    totalRead += r;
+                }
+
+                var line = Encoding.UTF8.GetString(reqBytes);
                 if (string.IsNullOrWhiteSpace(line)) return;
 
                 var request = JsonSerializer.Deserialize<IpcRequest>(line);
@@ -161,8 +192,11 @@ public sealed class TerminalIpcServer : IDisposable
                     ? await _handler(request)
                     : new IpcResponse { Success = false, ErrorMessage = "Invalid request" };
 
-                var responseJson = JsonSerializer.Serialize(response) + "\n";
+                var responseJson = JsonSerializer.Serialize(response);
                 var responseBytes = Encoding.UTF8.GetBytes(responseJson);
+                var lengthPrefix = BitConverter.GetBytes(responseBytes.Length);
+                
+                await stream.WriteAsync(lengthPrefix, token);
                 await stream.WriteAsync(responseBytes, token);
                 await stream.FlushAsync(token);
             }
@@ -185,7 +219,7 @@ public sealed class TerminalIpcServer : IDisposable
         pipeSecurity.AddAccessRule(new PipeAccessRule(usersSid, PipeAccessRights.ReadWrite, AccessControlType.Allow));
 
         return NamedPipeServerStreamAcl.Create(
-            TerminalIpcConstants.PipeName,
+            @"global\" + TerminalIpcConstants.PipeName,
             PipeDirection.InOut,
             NamedPipeServerStream.MaxAllowedServerInstances,
             PipeTransmissionMode.Byte,

docs/HARDWARE-TEST-SLK20R.md

@@ -123,3 +123,4 @@ If an enumerated slot returns a serial number that has already been registered b
 | USB Disconnect to UI State Update | < 500 ms | ~120 ms | PASSED |
 | Cable Re-insertion to Active Ready State | < 3000 ms | 2150 ms | PASSED |
 | Duplicate Scan Guard (30s lockout) | 100% rejection | 100% rejection (0 duplicate punches) | PASSED |
+| Windows Service startup persistence after reboot | Reliable | NOT TESTED YET IN HARDWARE (Requires real service installation test after machine reboot to verify background sync without login) | PENDING |