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/Common/ProcessRunner.cs

@@ -1,6 +1,7 @@
 namespace ElectronNET.Common
 {
     using System;
+    using System.Collections.Generic;
     using System.Diagnostics;
     using System.Diagnostics.CodeAnalysis;
     using System.Text;
@@ -26,6 +27,8 @@
         private readonly StringBuilder stdOut = new StringBuilder(4 * 1024);
         private readonly StringBuilder stdErr = new StringBuilder(4 * 1024);
 
+        public event EventHandler<string> LineReceived;
+
         private volatile ManualResetEvent stdOutEvent;
         private volatile ManualResetEvent stdErrEvent;
         private volatile Stopwatch stopwatch;
@@ -109,6 +112,11 @@
         public int? LastExitCode { get; private set; }
 
         public bool Run(string exeFileName, string commandLineArgs, string workingDirectory)
+        {
+            return this.Run(exeFileName, commandLineArgs, workingDirectory, null);
+        }
+
+        public bool Run(string exeFileName, string commandLineArgs, string workingDirectory, IDictionary<string, string> environmentVariables)
         {
             this.CommandLine = commandLineArgs;
             this.WorkingFolder = workingDirectory;
@@ -126,6 +134,14 @@
                 WorkingDirectory = workingDirectory
             };
 
+            if (environmentVariables != null)
+            {
+                foreach (var kv in environmentVariables)
+                {
+                    startInfo.EnvironmentVariables[kv.Key] = kv.Value;
+                }
+            }
+
             return this.Run(startInfo);
         }
 
@@ -571,6 +587,7 @@
             if (e.Data != null)
             {
                 Console.WriteLine("|| " + e.Data);
+                LineReceived?.Invoke(this, e.Data);
             }
             else
             {