test: prove a launcher installs the client from the live Gitea release

Lane=Live end-to-end verification against the real feed, using the production
updater the GUI button calls: ReleaseManifestClient.ProductionManifestUri, real
network, real SHA-256/size verification, real ZIP extraction, real atomic
activation. Asserts what the launcher actually does next — that
LauncherExecutableSet can resolve BOTH hosts out of the activated directory,
and that current.json names the installed version — rather than merely that
files exist.

Excluded from the bounded gate (Lane=Live needs the public feed reachable);
run deliberately after a release lands. Writes only under an isolated
temporary path set, never the caller's real launcher data directory.

tests/AcDream.Launcher.Core.Tests/Updates/LiveGiteaReleaseInstallTests.cs

@@ -0,0 +1,89 @@
+using AcDream.Launcher.Core.Orchestration;
+using AcDream.Launcher.Core.Profiles;
+using AcDream.Launcher.Core.Updates;
+using AcDream.Platform;
+
+namespace AcDream.Launcher.Core.Tests.Updates;
+
+/// <summary>
+/// End-to-end proof that a launcher installs the client from the real Gitea
+/// alpha release, using the PRODUCTION updater the GUI button calls — the same
+/// <see cref="ReleaseManifestClient.ProductionManifestUri"/>, real network,
+/// real SHA-256/size verification, real ZIP extraction and atomic activation.
+///
+/// <para>
+/// Lane=Live: it needs the public feed to be reachable, so the bounded gate
+/// excludes it. Run it deliberately after a release lands:
+/// <c>dotnet test tests/AcDream.Launcher.Core.Tests --filter Lane=Live</c>.
+/// Everything is written under an isolated temporary path set, never the
+/// caller's real launcher data directory.
+/// </para>
+/// </summary>
+public sealed class LiveGiteaReleaseInstallTests : IDisposable
+{
+    private readonly string _root = Path.Combine(
+        Path.GetTempPath(),
+        "acdream-live-release-install",
+        Guid.NewGuid().ToString("N"));
+    private readonly ApplicationPathSet _paths;
+    private readonly string _rid = LauncherRuntimeIdentity.DetectRid();
+
+    public LiveGiteaReleaseInstallTests() => _paths = UpdateTestData.Paths(_root);
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_root))
+        {
+            try { Directory.Delete(_root, recursive: true); } catch (IOException) { }
+        }
+    }
+
+    [Fact]
+    [Trait("Lane", "Live")]
+    public async Task InstallsTheAdvertisedClientFromTheLiveGiteaRelease()
+    {
+        using var http = new HttpClient();
+        using var source = new ReleaseManifestClient(TimeSpan.FromSeconds(30));
+        var versions = new ClientVersionStore(_paths);
+        var updater = new LauncherUpdater(
+            source,
+            http,
+            versions,
+            new LauncherSelfUpdateManager(_paths, http),
+            // Deliberately ancient so the feed always advertises something
+            // newer; this asserts the INSTALL path, not the version compare.
+            LauncherVersion.Parse("0.0.1"),
+            _rid,
+            Path.Combine(_root, "launcher"));
+
+        _ = await updater.InitializeAsync();
+
+        LauncherUpdateCheckResult check = await updater.CheckAsync();
+        Assert.True(
+            check.IsClientUpdateAvailable,
+            $"The live feed advertised no client for RID '{_rid}': {check.Status}");
+
+        ClientVersionResolution installed = await updater.InstallClientAsync(check);
+
+        Assert.True(installed.IsVerified, installed.Status);
+        Assert.Equal(check.Manifest.Version, installed.Version);
+        Assert.NotNull(installed.Directory);
+
+        // The launcher resolves its hosts out of the activated directory, so
+        // assert what it will actually look for rather than merely "files exist".
+        var executables = LauncherExecutableSet.FromCurrentVersionStore(versions);
+        Assert.True(
+            executables.GetAvailability(LaunchMode.Gui).IsAvailable,
+            "The graphical client is not launchable from the installed release.");
+        Assert.True(
+            executables.GetAvailability(LaunchMode.Headless).IsAvailable,
+            "The headless host is not launchable from the installed release.");
+
+        // current.json must point at exactly what was just activated.
+        Assert.True(File.Exists(versions.CurrentPointerPath));
+        Assert.Contains(
+            check.Manifest.Version.Value,
+            await File.ReadAllTextAsync(versions.CurrentPointerPath),
+            StringComparison.Ordinal);
+    }
+}