refactor(input): own pointer and callback lifetime

Move camera pointer, framebuffer resize, and retained/devtools input edges behind focused reversible owners. Preserve input priority while making shutdown deactivate callbacks before live-session retirement and retry physical detach without stranding transport teardown.

tests/AcDream.App.Tests/Rendering/FramebufferResizeControllerTests.cs

@@ -0,0 +1,76 @@
+using AcDream.App.Input;
+using AcDream.App.Rendering;
+
+namespace AcDream.App.Tests.Rendering;
+
+public sealed class FramebufferResizeControllerTests
+{
+    [Fact]
+    public void ResizePreservesViewportAspectCameraDevToolsOrder()
+    {
+        var calls = new List<string>();
+        var aspect = new ViewportAspectState();
+        var owner = new FramebufferResizeController(aspect);
+        owner.BindViewport(new Viewport(calls));
+        owner.BindCamera(new Camera(calls));
+        owner.BindDevTools(new DevTools(calls));
+
+        owner.Resize(1600, 900);
+
+        Assert.Equal(["viewport:1600x900", "camera:1.778", "devtools:1600x900"], calls);
+        Assert.Equal(1600f / 900f, aspect.Aspect, 5);
+    }
+
+    [Theory]
+    [InlineData(0, 720)]
+    [InlineData(1280, 0)]
+    [InlineData(-1, 720)]
+    [InlineData(1280, -1)]
+    public void NonPositiveFramebufferIsRejectedWithoutMutatingTargets(int width, int height)
+    {
+        var calls = new List<string>();
+        var aspect = new ViewportAspectState();
+        var owner = new FramebufferResizeController(aspect);
+        owner.BindViewport(new Viewport(calls));
+        owner.BindCamera(new Camera(calls));
+        owner.BindDevTools(new DevTools(calls));
+
+        owner.Resize(width, height);
+
+        Assert.Empty(calls);
+        Assert.Equal(16f / 9f, aspect.Aspect);
+    }
+
+    [Fact]
+    public void LateBindingDoesNotReplayEarlierResize()
+    {
+        var calls = new List<string>();
+        var owner = new FramebufferResizeController(new ViewportAspectState());
+        owner.Resize(1024, 768);
+
+        owner.BindViewport(new Viewport(calls));
+        owner.BindCamera(new Camera(calls));
+        owner.BindDevTools(new DevTools(calls));
+
+        Assert.Empty(calls);
+        owner.Resize(800, 600);
+        Assert.Equal(["viewport:800x600", "camera:1.333", "devtools:800x600"], calls);
+    }
+
+    private sealed class Viewport(List<string> calls) : IFramebufferViewportTarget
+    {
+        public void ResizeViewport(int width, int height) =>
+            calls.Add($"viewport:{width}x{height}");
+    }
+
+    private sealed class Camera(List<string> calls) : IFramebufferCameraTarget
+    {
+        public void SetAspect(float aspect) => calls.Add($"camera:{aspect:F3}");
+    }
+
+    private sealed class DevTools(List<string> calls) : IFramebufferDevToolsTarget
+    {
+        public void ResetLayout(int width, int height) =>
+            calls.Add($"devtools:{width}x{height}");
+    }
+}