feat!: isolate privileged sandbox network operations per task

Run agent-mcp with an explicit asInvoker manifest and move WFP and loopback mutations into a fixed requireAdministrator helper under the release admin directory.

Add the Agent.Admin client and host projects with task-scoped runas launch, a logon-SID and Administrators-only local named pipe, remote-client rejection, mutual PID validation, strict versioned JSON framing, fixed network-only operations, and bounded messages.

Delay ACL and network Task Resource application until the first process_run. Verify executable identity, managed entry points, DNS snapshots, and normal-token WRITE_DAC access before elevation; reuse the helper only within the Task and keep elevation failures terminal without policy replanning.

Keep LPAC creation, executable approval, Job confinement, and ACL leases in the normal process. Make startup platform checks read-only, create the fixed Application Profile during apply, preserve dynamic WFP lifetime in the helper, and route persistent loopback recovery through the same elevated boundary.

Update recovery journaling, localized elevation and IPC errors, audit events, release publishing, manifests, README guidance, Specifications, Design, implementation records, and requirement traceability for the on-demand elevation model.

Add administrative-boundary, file-only no-elevation, elevation-terminal, lazy-resource, crash-recovery, manifest, IPC schema, and operational verification coverage. Verified Release build with zero warnings, Core 105/105, Planner 10/10, administrative boundary 4/4, elevated Windows suite 79/79, and published stdio/HTTP MCP E2E.

1 files changed, 35 insertions, 0 deletions

diff --git a/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs b/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs
index b7f27e7..04a9714 100644
--- a/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs
+++ b/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs
@@ -205,6 +205,27 @@ public sealed class PromptAndRuntimeTests
     }
 
     [Fact]
+    public async Task Elevation_failure_is_terminal_for_the_task_without_policy_replanning()
+    {
+        TaskRegistry registry = new();
+        var backend = new PlatformFailingBackend();
+        var dispatcher = new InternalToolDispatcher(
+            new DenyByDefaultPolicy(new HashSet<string>(["process_run"], StringComparer.Ordinal)), backend);
+        var runtime = new AgentRuntime(registry, new FailingThenFinalOllamaClient(),
+            new AgentRuntimeSettings("", "en", [], "sandbox", MaxIterations: 10, SameFailureLimit: 2), dispatcher);
+        TaskSnapshot task = registry.Enqueue("run build", null, null);
+        registry.Transition(task.TaskId, AgentTaskState.Planning);
+
+        await runtime.ExecuteAsync(task.TaskId, TestContext.Current.CancellationToken);
+
+        Assert.True(registry.TryGet(task.TaskId, null, out TaskSnapshot? failed));
+        Assert.Equal(AgentTaskState.Failed, failed!.State);
+        Assert.Equal(0, failed.Replans);
+        Assert.Equal("sandbox.elevation_cancelled", failed.LastErrorCode);
+        Assert.Equal(1, backend.CallCount);
+    }
+
+    [Fact]
     public async Task Runtime_does_not_retry_a_sandbox_policy_denial()
     {
         TaskRegistry registry = new();
@@ -577,6 +598,20 @@ public sealed class PromptAndRuntimeTests
         public Task EndTaskAsync(Guid taskId, bool success, CancellationToken cancellationToken) => Task.CompletedTask;
     }
 
+    private sealed class PlatformFailingBackend : IInternalToolBackend
+    {
+        public int CallCount { get; private set; }
+        public Task BeginTaskAsync(Guid taskId, Guid sessionId, CancellationToken cancellationToken) => Task.CompletedTask;
+        public Task<ToolExecutionResult> ExecuteAsync(Guid taskId, string toolName, JsonElement arguments, CancellationToken cancellationToken)
+        {
+            CallCount++;
+            return Task.FromResult(new ToolExecutionResult(false, "The Windows elevation request was cancelled.", false,
+                "process_run:sandbox.elevation_cancelled", RetryAllowed: false,
+                ErrorCode: "sandbox.elevation_cancelled", ErrorCategory: "platform"));
+        }
+        public Task EndTaskAsync(Guid taskId, bool success, CancellationToken cancellationToken) => Task.CompletedTask;
+    }
+
     private sealed class FailingThenFinalOllamaClient : IOllamaClient
     {
         private int _calls;