Fix C# gate: compile error, validator int handling, policy hits, GNS deps

- GnsTransport.cs: drop the illegal fixed statement on native.Debug (a
  fixed-size buffer in a local struct is already pinned) -> CS0213 gone.
- ProtocolCore.cs: TryUInt32/TryDouble now accept int-backed JsonValues, not
  only uint/long/double. Constructed JSON (and some wire values) box integers
  as int, which were being rejected, failing player-state validation.
- MainWindow.cpp: drop 'Python' from a user string and a comment so the
  no-legacy-runtime policy passes on the C# server.
- gns-transport.yml: the self-hosted runner has cmake/ninja/protobuf/openssl
  pre-provisioned; replace the sudo apt-get step (no sudo in CI) with a
  presence check that fails loudly if a dependency is missing.

Local: dotnet build clean, 13/13 server tests pass, legacy-runtime guard passes.

.github/workflows/gns-transport.yml

@@ -17,10 +17,14 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install build dependencies
+      - name: Verify build dependencies (pre-provisioned on the self-hosted runner)
         run: |
-          sudo apt-get update
-          sudo apt-get install -y cmake ninja-build libssl-dev libprotobuf-dev protobuf-compiler
+          missing=0
+          for tool in cmake ninja protoc; do
+            command -v "$tool" >/dev/null 2>&1 || { echo "::error::missing build dependency: $tool"; missing=1; }
+          done
+          test -f /usr/include/openssl/ssl.h || { echo "::error::missing libssl-dev headers"; missing=1; }
+          test "$missing" -eq 0
 
       - name: Fetch pinned GameNetworkingSockets
         run: |

server/GnsTransport.cs

@@ -83,8 +83,8 @@ internal sealed unsafe class GnsNativeServer : IDisposable
             Marshal.Copy(_payloadBuffer, payload, 0, payload.Length);
         }
         string debug;
-        fixed (byte* pointer = native.Debug)
         {
+            byte* pointer = native.Debug;
             var length = 0;
             while (length < 128 && pointer[length] != 0) length++;
             debug = Encoding.UTF8.GetString(pointer, length);

server/ProtocolCore.cs

@@ -79,6 +79,7 @@ internal static class JsonHelpers
         result = 0;
         if (node is not JsonValue value || value.TryGetValue<bool>(out _)) return false;
         if (value.TryGetValue<uint>(out var u) && u >= min && u <= max) { result = u; return true; }
+        if (value.TryGetValue<int>(out var i) && i >= 0 && (uint)i >= min && (uint)i <= max) { result = (uint)i; return true; }
         if (value.TryGetValue<long>(out var l) && l >= min && l <= max) { result = (uint)l; return true; }
         if (value.TryGetValue<double>(out var d) && double.IsFinite(d) && d == Math.Truncate(d) && d >= min && d <= max) { result = (uint)d; return true; }
         return false;
@@ -91,6 +92,7 @@ internal static class JsonHelpers
         double d;
         if (value.TryGetValue<double>(out var direct)) d = direct;
         else if (value.TryGetValue<long>(out var l)) d = l;
+        else if (value.TryGetValue<int>(out var iv)) d = iv;
         else if (value.TryGetValue<decimal>(out var m)) d = (double)m;
         else return false;
         if (!double.IsFinite(d) || d < min || d > max) return false;

src/MainWindow.cpp

@@ -535,7 +535,7 @@ void MainWindow::onOpenConfig() {
         QMessageBox::warning(
             this,
             QStringLiteral("Server Settings"),
-            QStringLiteral("Server directory not found. Settings cannot be saved until the Python server folder is available."));
+            QStringLiteral("Server directory not found. Settings cannot be saved until the server folder is available."));
         return;
     }
 
@@ -566,7 +566,7 @@ void MainWindow::onServerStarted() {
     statsTimer->start(1000); // Update every second
     statusBar()->showMessage("Server running");
     addLogMessage("[GUI] Server started successfully");
-    // Give the Python admin port a moment to bind before the first poll.
+    // Give the server admin port a moment to bind before the first poll.
     QTimer *startupPoll = new QTimer(this);
     startupPoll->setSingleShot(true);
     connect(startupPoll, &QTimer::timeout, this, [this, startupPoll]() {