test(launcher): Campaign LA enforce composer-host contract

tests/Fixtures/campaign-la/LauncherCoreSessionConfigFixture.cs

@@ -0,0 +1,58 @@
+using AcDream.Launcher.Core.Launching;
+using AcDream.Launcher.Core.Profiles;
+using AcDream.Platform;
+
+namespace AcDream.Tests.Fixtures.CampaignLa;
+
+/// <summary>
+/// Produces one real Launcher.Core session document that is compiled into
+/// both host test suites. Keeping composition in one linked fixture makes the
+/// LA1/LA3 anti-drift gate prove that App and Headless accept the identical
+/// composer output rather than two hand-maintained lookalikes.
+/// </summary>
+internal static class LauncherCoreSessionConfigFixture
+{
+    internal const string Password = "must-not-be-serialized";
+
+    internal static string Compose()
+    {
+        var server = new ServerProfile
+        {
+            Name = "Composer Server",
+            Host = "composer.example",
+            Port = 9010,
+        };
+        var account = new AccountProfile
+        {
+            Account = "composer-account",
+            Password = Password,
+        };
+        var character = new CharacterProfile
+        {
+            Name = "Composer Character",
+            Id = "0x50000001",
+            LaunchMode = LaunchMode.Headless,
+            Plugins = ["ComposerPlugin"],
+            LoginCommands = ["/composer command"],
+        };
+        var install = new LauncherInstallRecord(
+            "composer-dats",
+            "composer-dats/acdream.pak");
+        var paths = new ApplicationPathSet(
+            Path.Combine(Path.GetTempPath(), "composer-config"),
+            Path.Combine(Path.GetTempPath(), "composer-data"),
+            Path.Combine(Path.GetTempPath(), "composer-cache"),
+            LegacyConfigDirectory: null);
+
+        ComposedSessionConfig composed = SessionConfigComposer.Compose(
+            server,
+            account,
+            character,
+            install,
+            paths,
+            "composer-contract",
+            loginCommandDelayMs: 625);
+
+        return SessionConfigComposer.Serialize(composed.Document);
+    }
+}