Extract a per-user background host so indexing can later run outside the window.

Keep the GUI as the index writer for now; mutex, named pipe, and opt-in logon autostart prepare Explorer.Host.exe without two SQLite writers.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/Explorer.Hosting.Tests/CoreRegistrationTests.cs

@@ -0,0 +1,48 @@
+using Explorer.Contracts;
+using Explorer.Domain;
+using Explorer.Domain.Abstractions;
+using Explorer.Hosting;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Explorer.Hosting.Tests;
+
+public class CoreRegistrationTests
+{
+    [Fact]
+    public async Task AddExplorerCore_registers_workbench_without_clipboard()
+    {
+        var dir = Path.Combine(Path.GetTempPath(), "ew-hosting", Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(dir);
+        try
+        {
+            var services = new ServiceCollection();
+            services.AddLogging();
+            services.AddSingleton<IAppEnvironment>(new TempEnv(dir));
+            services.AddExplorerCore();
+            await using var sp = services.BuildServiceProvider();
+            Assert.NotNull(sp.GetService<IWorkbenchHost>());
+            Assert.NotNull(sp.GetService<IIndexingHost>());
+            Assert.NotNull(sp.GetService<ITransferHost>());
+            Assert.Null(sp.GetService<IOsClipboard>());
+        }
+        finally
+        {
+            try { Directory.Delete(dir, true); } catch { /* ignore */ }
+        }
+    }
+
+    private sealed class TempEnv : IAppEnvironment
+    {
+        public TempEnv(string dir)
+        {
+            DataDirectory = dir;
+            DatabasePath = Path.Combine(dir, "index.db");
+            LogDirectory = Path.Combine(dir, "logs");
+            Directory.CreateDirectory(LogDirectory);
+        }
+
+        public string DataDirectory { get; }
+        public string DatabasePath { get; }
+        public string LogDirectory { get; }
+    }
+}

tests/Explorer.Hosting.Tests/Explorer.Hosting.Tests.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0-windows</TargetFramework>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Logging" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Explorer.Application\Explorer.Application.csproj" />
+    <ProjectReference Include="..\..\src\Explorer.Contracts\Explorer.Contracts.csproj" />
+    <ProjectReference Include="..\..\src\Explorer.Domain\Explorer.Domain.csproj" />
+    <ProjectReference Include="..\..\src\Explorer.Hosting\Explorer.Hosting.csproj" />
+  </ItemGroup>
+</Project>

tests/Explorer.Hosting.Tests/HostLogonAutostartTests.cs

@@ -0,0 +1,19 @@
+using Explorer.Hosting;
+
+namespace Explorer.Hosting.Tests;
+
+public class HostLogonAutostartTests
+{
+    [Fact]
+    public void Create_args_are_per_user_logon_not_system_service()
+    {
+        var args = HostLogonAutostart.CreateTaskArgs(@"C:\Tools\Explorer.Host.exe");
+        Assert.Contains("/SC", args);
+        Assert.Contains("ONLOGON", args);
+        Assert.Contains("/RL", args);
+        Assert.Contains("LIMITED", args);
+        Assert.Contains(HostLogonAutostart.TaskName, args);
+        Assert.DoesNotContain("ONSTART", args);
+        Assert.DoesNotContain("/RU", args);
+    }
+}

tests/Explorer.Hosting.Tests/WorkbenchPipeTests.cs

@@ -0,0 +1,76 @@
+using Explorer.Application;
+using Explorer.Contracts;
+using Explorer.Domain;
+using Explorer.Hosting.Ipc;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace Explorer.Hosting.Tests;
+
+public class WorkbenchPipeTests
+{
+    [Fact]
+    public void Handle_forwards_indexing_and_transfer_calls()
+    {
+        var indexing = new FakeIndexing();
+        var transfers = new FakeTransfers();
+        var server = new WorkbenchPipeServer(
+            new WorkbenchHost(indexing, transfers),
+            new WorkbenchIpcOptions { PipeName = "ew-test" },
+            NullLogger<WorkbenchPipeServer>.Instance);
+
+        var ping = server.Handle(new IpcEnvelope { V = WorkbenchIpc.ProtocolVersion, Op = "Ping" });
+        Assert.True(ping.Ok);
+
+        var scan = server.Handle(new IpcEnvelope { V = WorkbenchIpc.ProtocolVersion, Op = "Indexing.EnqueueFullScan", N = 42 });
+        Assert.True(scan.Ok);
+        Assert.Equal(42, indexing.FullScanId);
+
+        var pause = server.Handle(new IpcEnvelope { V = WorkbenchIpc.ProtocolVersion, Op = "Transfers.PauseAll" });
+        Assert.True(pause.Ok);
+        Assert.True(transfers.PausedAll);
+
+        var paused = server.Handle(new IpcEnvelope { V = WorkbenchIpc.ProtocolVersion, Op = "Transfers.IsPaused" });
+        Assert.True(paused.Paused);
+    }
+
+    [Fact]
+    public void Handle_rejects_other_protocol_versions()
+    {
+        var server = new WorkbenchPipeServer(
+            new WorkbenchHost(new FakeIndexing(), new FakeTransfers()),
+            new WorkbenchIpcOptions(),
+            NullLogger<WorkbenchPipeServer>.Instance);
+        var reply = server.Handle(new IpcEnvelope { V = 99, Op = "Ping" });
+        Assert.False(reply.Ok);
+        Assert.Contains("99", reply.Error);
+    }
+
+    private sealed class FakeIndexing : IIndexingHost
+    {
+        public long FullScanId { get; private set; }
+        public event EventHandler<ScanProgress>? ProgressChanged = delegate { };
+        public void EnqueueFullScan(long sourceId) => FullScanId = sourceId;
+        public void EnqueueFolderScan(long sourceId, string pathRel) { }
+        public void EnqueueReconcile(long sourceId, string pathRel) { }
+        public void Cancel(long sourceId) { }
+    }
+
+    private sealed class FakeTransfers : ITransferHost
+    {
+        public bool PausedAll { get; private set; }
+        public event EventHandler? Changed = delegate { };
+        public event EventHandler<TransferJob>? JobFinished = delegate { };
+        public bool IsPaused => PausedAll;
+        public IReadOnlyList<TransferJob> Snapshot() => [];
+        public void PauseAll() => PausedAll = true;
+        public void ResumeAll() => PausedAll = false;
+        public void Pause(long jobId) { }
+        public void Resume(long jobId) { }
+        public void Retry(long jobId) { }
+        public void Cancel(long jobId) { }
+        public void Dismiss(long jobId) { }
+        public void ClearFinished() { }
+        public bool MoveUp(long jobId) => false;
+        public bool MoveDown(long jobId) => false;
+    }
+}