feat: add secure WP7-02 external executor

supervisor/Dada.Supervisor.Tests/Program.cs

@@ -16,6 +16,12 @@ internal static class Program
             return await RunCredentialChildAsync();
         }
 
+        if (args.FirstOrDefault() == "--credential-echo")
+        {
+            Console.Write(await Console.In.ReadToEndAsync());
+            return 0;
+        }
+
         if (args.FirstOrDefault() == "--instance-probe")
         {
             using var instance = await SingleInstanceCoordinator.TryAcquireAsync(args[1], args[2]);
@@ -120,6 +126,28 @@ internal static class Program
 
         var workerProbe = await LaunchCredentialProbeAsync(ChildRole.Worker, store);
         EqualSequence(new[] { CredentialCatalog.WorkerAiGateway }, workerProbe.Names, "Worker credential scope");
+        var leakProbe = await CredentialProcessLauncher.RunToCompletionAsync(
+            new ProcessStartInfo(Environment.ProcessPath!, "--credential-echo"), ChildRole.Worker, store);
+        True(leakProbe.SensitiveOutputDetected, "credential echo must be detected");
+        Equal(string.Empty, leakProbe.StandardOutput, "credential echo output discarded");
+        Equal(string.Empty, leakProbe.StandardError, "credential echo error discarded");
+
+        var externalArguments = new[]
+        {
+            "--service", "ai-gateway-service-id",
+            "--model", "gpt-image-2",
+            "--run-id", "wp7-02-supervisor-probe",
+            "--candidate-record", "candidate.json",
+            "--config-manifest", "config.json",
+            "--evidence-dir", "evidence",
+            "--max-real-calls", "120",
+            "--confirm-controlled-real",
+            "--execute-controlled-real",
+        };
+        EqualSequence(externalArguments, ControlledExternalValidationLauncher.ValidateArguments(externalArguments), "controlled external argument allowlist");
+        Throws<ArgumentException>(
+            () => ControlledExternalValidationLauncher.ValidateArguments(externalArguments.Where(value => value != "--confirm-controlled-real").ToArray()),
+            "controlled external confirmation required");
 
         store.Delete(CredentialCatalog.WorkerAiGateway);
         await ThrowsAsync<MissingCredentialException>(
@@ -166,15 +194,10 @@ internal static class Program
 
     private static async Task<CredentialProbe> LaunchCredentialProbeAsync(ChildRole role, ICredentialStore store)
     {
-        var startInfo = new ProcessStartInfo(Environment.ProcessPath!, "--credential-child")
-        {
-            RedirectStandardOutput = true,
-        };
-        using var process = await CredentialProcessLauncher.StartAsync(startInfo, role, store);
-        var output = await process.StandardOutput.ReadToEndAsync();
-        await process.WaitForExitAsync();
-        Equal(0, process.ExitCode, "credential child exit code");
-        return JsonSerializer.Deserialize<CredentialProbe>(output, new JsonSerializerOptions { PropertyNameCaseInsensitive = true })
+        var result = await CredentialProcessLauncher.RunToCompletionAsync(new ProcessStartInfo(Environment.ProcessPath!, "--credential-child"), role, store);
+        Equal(0, result.ExitCode, "credential child exit code");
+        False(result.SensitiveOutputDetected, "credential child output contains injected value");
+        return JsonSerializer.Deserialize<CredentialProbe>(result.StandardOutput, new JsonSerializerOptions { PropertyNameCaseInsensitive = true })
             ?? throw new InvalidOperationException("Credential child returned invalid JSON.");
     }
 
@@ -355,6 +378,19 @@ internal static class Program
         throw new InvalidOperationException(message);
     }
 
+    private static void Throws<TException>(Action action, string message) where TException : Exception
+    {
+        try
+        {
+            action();
+        }
+        catch (TException)
+        {
+            return;
+        }
+        throw new InvalidOperationException(message);
+    }
+
     private sealed record CredentialProbe(string[] Names, bool EnvironmentContainsMarker, bool ArgumentsContainMarker);
 
     private sealed class TestCredentialStore : ICredentialStore