refactor(streaming): own presentation retirement in pipeline

Move full and near-tier presentation retirement out of GameWindow and into a concrete pipeline-owned stage mapper. Harden the retry ledger against reentrancy and committed visibility observer failures, enforce a single state/resource ownership graph, and split concrete versus legacy controller construction so callbacks cannot be silently ignored.

Co-authored-by: Codex <codex@openai.com>

tests/AcDream.App.Tests/Streaming/LandblockPresentationPipelineTests.cs

@@ -12,6 +12,63 @@ namespace AcDream.App.Tests.Streaming;
 
 public sealed class LandblockPresentationPipelineTests
 {
+    [Fact]
+    public void ControllerRejectsPresentationPipelineFromForeignWorldState()
+    {
+        var controllerState = new GpuWorldState();
+        var foreignState = new GpuWorldState();
+        var foreignPipeline = new LandblockPresentationPipeline(
+            static (_, _) => { },
+            foreignState);
+
+        Assert.Throws<ArgumentException>(() => new StreamingController(
+            enqueueLoad: static (_, _, _) => { },
+            enqueueUnload: static (_, _) => { },
+            drainCompletions: static _ => Array.Empty<LandblockStreamResult>(),
+            controllerState,
+            nearRadius: 0,
+            farRadius: 0,
+            presentationPipeline: foreignPipeline));
+    }
+
+    [Fact]
+    public void LegacyPipelineRejectsRetirementCoordinatorFromForeignWorldState()
+    {
+        var pipelineState = new GpuWorldState();
+        var foreignCoordinator = new LandblockRetirementCoordinator(
+            new GpuWorldState(),
+            static _ => { });
+
+        Assert.Throws<ArgumentException>(() =>
+            new LandblockPresentationPipeline(
+                static (_, _) => { },
+                pipelineState,
+                retirementCoordinator: foreignCoordinator));
+    }
+
+    [Fact]
+    public void ControllerConcreteConstructorHasNoLegacyPresentationParameters()
+    {
+        string[] legacyNames =
+        [
+            "applyTerrain",
+            "removeTerrain",
+            "demoteNearLayer",
+            "onLandblockLoaded",
+            "ensureEnvCellMeshes",
+            "retirementCoordinator",
+        ];
+
+        System.Reflection.ConstructorInfo concrete = Assert.Single(
+            typeof(StreamingController).GetConstructors(),
+            constructor => constructor.GetParameters().Any(
+                parameter => parameter.Name == "presentationPipeline"));
+        string[] names = concrete.GetParameters()
+            .Select(parameter => parameter.Name!)
+            .ToArray();
+        Assert.DoesNotContain(names, legacyNames.Contains);
+    }
+
     [Fact]
     public void Loaded_PreservesPresentationSpatialPinReplayAndLiveRecoveryOrder()
     {