Automatic Port Selection and Secured Communication (#1038)

Adds dynamic OS-selected socket port handling and secured Electron/.NET communication.

The dotnet-first startup flow now generates the auth token on the .NET side and passes it to Electron through an environment variable. Electron reports the selected socket port through a temporary startup-info file, avoiding any dependency on parsing Electron console output.

Also avoids logging backend startup parameters because they include the auth token.

src/ElectronNET.API/Bridge/SocketIOConnection.cs

@@ -3,10 +3,12 @@
 namespace ElectronNET.API;
 
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using ElectronNET.API.Serialization;
 using SocketIO.Serializer.SystemTextJson;
 using SocketIO = SocketIOClient.SocketIO;
+using SocketIOOptions = SocketIOClient.SocketIOOptions;
 
 internal class SocketIOConnection : ISocketConnection
 {
@@ -14,9 +16,16 @@ internal class SocketIOConnection : ISocketConnection
     private readonly object _lockObj = new object();
     private bool _isDisposed;
 
-    public SocketIOConnection(string uri)
+    public SocketIOConnection(string uri, string authorization)
     {
-        _socket = new SocketIO(uri);
+        var opts = string.IsNullOrEmpty(authorization) ? new SocketIOOptions() : new SocketIOOptions
+        {
+            ExtraHeaders = new Dictionary<string, string>
+            {
+                ["authorization"] = authorization
+            },
+        };
+        _socket = new SocketIO(uri, opts);
         _socket.Serializer = new SystemTextJsonSerializer(ElectronJson.Options);
         // Use default System.Text.Json serializer from SocketIOClient.
         // Outgoing args are normalized to camelCase via SerializeArg in Emit.