refactor(ui): own retained controller lifetimes

tests/AcDream.App.Tests/UI/Layout/SelectedObjectControllerTests.cs

@@ -82,7 +82,15 @@ public class SelectedObjectControllerTests
             => SelectedObjectController.Bind(
                 layout,
                 subscribeSelectionChanged: h => SelectionHandler = h,
+                unsubscribeSelectionChanged: h =>
+                {
+                    if (SelectionHandler == h) SelectionHandler = null;
+                },
                 subscribeHealthChanged:    h => HealthHandler = h,
+                unsubscribeHealthChanged: h =>
+                {
+                    if (HealthHandler == h) HealthHandler = null;
+                },
                 isHealthTarget:  g => HealthTargetMap.TryGetValue(g, out var v) && v,
                 name:            g => NameMap.TryGetValue(g, out var v) ? v : null,
                 healthPercent:   g => HealthMap.TryGetValue(g, out var v) ? v : 1f,
@@ -403,4 +411,23 @@ public class SelectedObjectControllerTests
         h.FireSelection(null);
         Assert.Equal(0f, healthMeterEl.Fill() ?? 0f);
     }
+
+    [Fact]
+    public void Dispose_UnsubscribesBothHandlers_AndIsIdempotent()
+    {
+        var (layout, _, _, healthMeterEl) = FakeLayout();
+        var h = new Harness();
+        h.HealthTargetMap[0xAA09u] = true;
+        var controller = h.Bind(layout);
+
+        controller.Dispose();
+        controller.Dispose();
+        h.FireSelection(0xAA09u);
+        h.FireHealth(0xAA09u, 0.5f);
+
+        Assert.Null(h.SelectionHandler);
+        Assert.Null(h.HealthHandler);
+        Assert.False(healthMeterEl.Visible);
+        Assert.Empty(h.QueryHealthCalls);
+    }
 }

tests/AcDream.App.Tests/UI/Layout/ToolbarControllerTests.cs

@@ -98,6 +98,28 @@ public class ToolbarControllerTests
         Assert.Equal(0x5002u, slots[Row1[2]].Cell.ItemId); // rebound on ItemAdded
     }
 
+    [Fact]
+    public void Dispose_UnsubscribesDeferredRebind_AndIsIdempotent()
+    {
+        var (layout, slots, _) = FakeToolbar();
+        var repo = new ClientObjectTable();
+        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
+        { new(Index: 2, ObjectGuid: 0x5002u, SpellId: 0, Layer: 0) };
+        var controller = ToolbarController.Bind(layout, repo, () => shortcuts,
+            iconIds: (_,_,_,_,_) => 0x88u, useItem: _ => { });
+
+        controller.Dispose();
+        controller.Dispose();
+        repo.AddOrUpdate(new ClientObject
+        {
+            ObjectId = 0x5002u,
+            WeenieClassId = 1u,
+            IconId = 0x06005678u,
+        });
+
+        Assert.Equal(0u, slots[Row1[2]].Cell.ItemId);
+    }
+
     [Fact]
     public void Click_emitsUseForBoundItem()
     {

tests/AcDream.App.Tests/UI/RetailWindowManagerTests.cs

@@ -179,6 +179,28 @@ public sealed class RetailWindowManagerTests
         Assert.Equal(1, secondController.DisposeCount);
     }
 
+    [Fact]
+    public void AttachController_AfterRegistration_DeliversVisibilityAndOwnsDisposal()
+    {
+        var root = new UiRoot { Width = 800, Height = 600 };
+        var frame = new UiPanel { Width = 100, Height = 100 };
+        root.AddChild(frame);
+        RetailWindowHandle handle = root.RegisterWindow("inventory", frame);
+        var controller = new RecordingController();
+
+        root.WindowManager.AttachController("inventory", controller);
+
+        Assert.Same(controller, handle.Controller);
+        Assert.Equal(1, controller.ShownCount);
+        Assert.Throws<InvalidOperationException>(() =>
+            root.WindowManager.AttachController("inventory", new RecordingController()));
+
+        root.WindowManager.Dispose();
+        root.WindowManager.Dispose();
+        Assert.Equal(1, controller.HiddenCount);
+        Assert.Equal(1, controller.DisposeCount);
+    }
+
     private sealed class RecordingController : IRetainedPanelController
     {
         public int ShownCount { get; private set; }

tests/AcDream.App.Tests/UI/RetainedPanelControllerGroupTests.cs

@@ -0,0 +1,42 @@
+using System.Collections.Generic;
+using AcDream.App.UI;
+
+namespace AcDream.App.Tests.UI;
+
+public sealed class RetainedPanelControllerGroupTests
+{
+    [Fact]
+    public void Lifecycle_ForwardsInOwnershipOrder_AndDisposesInReverseExactlyOnce()
+    {
+        var calls = new List<string>();
+        var first = new RecordingController("first", calls);
+        var second = new RecordingController("second", calls);
+        var group = new RetainedPanelControllerGroup(first, second);
+        var focus = new UiPanel();
+
+        group.OnShown();
+        group.OnDescendantFocusChanged(focus);
+        group.OnHidden();
+        group.Dispose();
+        group.Dispose();
+
+        Assert.Equal(
+        [
+            "first:shown", "second:shown",
+            "first:focus", "second:focus",
+            "second:hidden", "first:hidden",
+            "second:dispose", "first:dispose",
+        ], calls);
+    }
+
+    private sealed class RecordingController(
+        string name,
+        List<string> calls) : IRetainedPanelController
+    {
+        public void OnShown() => calls.Add($"{name}:shown");
+        public void OnHidden() => calls.Add($"{name}:hidden");
+        public void OnDescendantFocusChanged(UiElement? focusedDescendant)
+            => calls.Add($"{name}:focus");
+        public void Dispose() => calls.Add($"{name}:dispose");
+    }
+}