Refactor render graph error handling and resource APIs

- RenderGraph.Compile/Execute now return Error for better failure detection; error handling is propagated throughout compiler and executor.
- Renamed ScheduleReleaseResource to ReleaseResource for clarity; updated all usages.
- ResourceManager now calls ReleaseResource directly on Mesh, Material, and Shader types.
- Camera exposes Actual/Virtual size properties and Render returns Error.
- RenderingContext now uses IResourceManager for mesh/resource ops.
- Replaced custom BinaryWriter with BufferWriter in RenderGraphHasher.
- Improved variable naming, interface signatures, and code formatting.
- Added Error extension for IsSuccess/IsFailure.
- Minor FMOD/native interop and test code cleanups.
- No breaking API changes except for new Error return values on some methods.

src/Editor/Ghost.Editor/ActivationHandler.cs

@@ -1,9 +1,6 @@
-using Ghost.Editor.Core;
-using Ghost.Editor.Core.Contracts;
 using Ghost.Editor.Core.Utilities;
 using Ghost.Editor.Models;
 using Ghost.Engine;
-using Microsoft.UI.Xaml;
 using System.Reflection;
 
 namespace Ghost.Editor;