fix: PR 322 review fixes - overlay visibility, TCS race, JsonDocument disposal, error logging, UX improvements

- QrScannerPage: Set IsVisible=true on all 4 overlay BoxViews in LayoutOverlays()
- QrScannerService: Guard against TCS race condition on concurrent ScanAsync() calls
- Settings.razor: Dispose JsonDocument with 'using', add StateHasChanged after ShowStatus,
  log errors in TryGenerateFiestaPairingString, check WsBridgeServer.IsRunning after Start,
  show pairing string inline in Direct Connection section
- Dashboard.razor: Dispose JsonDocument with 'using'
- PolyPilot.csproj: Pin QRCoder=1.6.0 and ZXing.Net.Maui.Controls=0.4.0

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: PureWeen

PolyPilot/Components/Pages/Dashboard.razor

@@ -584,7 +584,7 @@
         try
         {
             // Try JSON format first: { "url": "...", "token": "...", "lanUrl": "...", "lanToken": "..." }
-            var doc = System.Text.Json.JsonDocument.Parse(result);
+            using var doc = System.Text.Json.JsonDocument.Parse(result);
             if (doc.RootElement.TryGetProperty("url", out var urlProp))
                 mobileRemoteUrl = urlProp.GetString() ?? "";
             if (doc.RootElement.TryGetProperty("token", out var tokenProp))

PolyPilot/Components/Pages/Settings.razor

@@ -271,6 +271,29 @@
                             </div>
                         }
 
+                        @if (fiestaPairingString != null)
+                        {
+                            <div class="tunnel-url">
+                                <label>Pairing string:</label>
+                                <code class="token-value @(showFiestaPairingString ? "" : "blurred")">@fiestaPairingString</code>
+                                <button class="copy-btn" @onclick="() => showFiestaPairingString = !showFiestaPairingString"
+                                        title="@(showFiestaPairingString ? "Hide" : "Reveal")">
+                                    @if (showFiestaPairingString)
+                                    {
+                                        <svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M17.94 17.94A10.07 10.07 0 0 1 12 20c-7 0-11-8-11-8a18.45 18.45 0 0 1 5.06-5.94M9.9 4.24A9.12 9.12 0 0 1 12 4c7 0 11 8 11 8a18.5 18.5 0 0 1-2.16 3.19m-6.72-1.07a3 3 0 1 1-4.24-4.24"/><line x1="1" y1="1" x2="23" y2="23"/></svg>
+                                    }
+                                    else
+                                    {
+                                        <svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M1 12s4-8 11-8 11 8 11 8-4 8-11 8-11-8-11-8z"/><circle cx="12" cy="12" r="3"/></svg>
+                                    }
+                                </button>
+                                <button class="copy-btn" @onclick="CopyFiestaPairingString" title="Copy to clipboard">
+                                    <svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="9" y="9" width="13" height="13" rx="2" ry="2"/><path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"/></svg>
+                                </button>
+                            </div>
+                            <p class="hint">Paste this string into the hub machine's Settings → Fiesta Workers → "Paste pairing string" field.</p>
+                        }
+
                         @if (!string.IsNullOrEmpty(directQrCodeDataUri))
                         {
                             <div class="qr-code">
@@ -1126,7 +1149,7 @@
         string? url = null;
         try
         {
-            var doc = System.Text.Json.JsonDocument.Parse(result);
+            using var doc = System.Text.Json.JsonDocument.Parse(result);
             if (doc.RootElement.TryGetProperty("url", out var urlProp))
                 url = urlProp.GetString();
             if (doc.RootElement.TryGetProperty("token", out var tokenProp))
@@ -1155,6 +1178,7 @@
             settings.RemoteUrl = url;
 
         ShowStatus("QR code scanned!", "success");
+        StateHasChanged();
     }
 
     private async Task TunnelLogin()
@@ -1351,8 +1375,16 @@
 
     private void TryGenerateFiestaPairingString()
     {
-        try { fiestaPairingString = FiestaService.GeneratePairingString(); }
-        catch { fiestaPairingString = null; }
+        try
+        {
+            fiestaPairingString = FiestaService.GeneratePairingString();
+        }
+        catch (Exception ex)
+        {
+            fiestaPairingString = null;
+            Console.WriteLine($"[Settings] Failed to generate pairing string: {ex.Message}");
+            ShowStatus($"Could not generate pairing string: {ex.Message}", "error", 8000);
+        }
     }
 
     private async Task CopyFiestaPairingString()
@@ -1564,6 +1596,11 @@
         WsBridgeServer.ServerPassword = settings.ServerPassword;
         WsBridgeServer.SetCopilotService(CopilotService);
         WsBridgeServer.Start(DevTunnelService.BridgePort, settings.Port);
+        if (!WsBridgeServer.IsRunning)
+        {
+            ShowStatus($"Failed to start bridge server on port {DevTunnelService.BridgePort} — the port may already be in use.", "error", 10000);
+            return;
+        }
         settings.DirectSharingEnabled = true;
         settings.Save();
         GenerateDirectQrCode();

PolyPilot/PolyPilot.csproj

@@ -81,8 +81,8 @@
         <PackageReference Include="Microsoft.Maui.Essentials.AI" Version="10.0.50-ci.main.26126.2" />
         <PackageReference Include="sqlite-net-pcl" Version="1.9.172" />
         <PackageReference Include="SQLitePCLRaw.bundle_green" Version="2.1.11" />
-        <PackageReference Include="QRCoder" Version="*" />
-        <PackageReference Include="ZXing.Net.Maui.Controls" Version="*" />
+        <PackageReference Include="QRCoder" Version="1.6.0" />
+        <PackageReference Include="ZXing.Net.Maui.Controls" Version="0.4.0" />
         <PackageReference Include="Redth.MauiDevFlow.Agent" Version="0.12.1" />
         <PackageReference Include="Redth.MauiDevFlow.Blazor" Version="0.12.1" />
     </ItemGroup>

PolyPilot/QrScannerPage.xaml.cs

@@ -56,6 +56,11 @@ private void LayoutOverlays(double pageWidth, double pageHeight)
         overlayRight.WidthRequest = pageWidth - left - cutoutSize;
         overlayRight.HeightRequest = cutoutSize;
         overlayRight.Margin = new Thickness(0, top, 0, 0);
+
+        overlayTop.IsVisible = true;
+        overlayBottom.IsVisible = true;
+        overlayLeft.IsVisible = true;
+        overlayRight.IsVisible = true;
     }
 
     protected override async void OnAppearing()

PolyPilot/Services/QrScannerService.cs

@@ -10,6 +10,9 @@ public class QrScannerService
 
     public Task<string?> ScanAsync()
     {
+        if (_tcs != null && !_tcs.Task.IsCompleted)
+            return _tcs.Task;
+
         _tcs = new TaskCompletionSource<string?>();
 
         MainThread.BeginInvokeOnMainThread(async () =>