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/Runtime/Ghost.Core/Utilities/BufferWriter.cs

@@ -0,0 +1,53 @@
+using Misaki.HighPerformance.LowLevel.Buffer;
+using Misaki.HighPerformance.LowLevel.Collections;
+using System.Runtime.CompilerServices;
+
+namespace Ghost.Core.Utilities;
+
+public struct BufferWriter : IDisposable
+{
+    private UnsafeList<byte> _buffer;
+    private int _position;
+
+    public int Position
+    {
+        readonly get => _position;
+        set => _position = value;
+    }
+
+    public BufferWriter(int initialCapacity, AllocationHandle allocationHandle)
+    {
+        _buffer = new UnsafeList<byte>(initialCapacity, allocationHandle);
+        _position = 0;
+    }
+
+    public unsafe void Write<T>(T value)
+        where T : unmanaged
+    {
+        Unsafe.WriteUnaligned(ref _buffer[_position], value);
+        _position += sizeof(T);
+    }
+
+    public void WriteBytes(ReadOnlySpan<byte> data)
+    {
+        data.CopyTo(_buffer.AsSpan().Slice(_position, data.Length));
+        _position += data.Length;
+    }
+
+    public Span<byte> ReserveSpan(int length)
+    {
+        var span = _buffer.AsSpan().Slice(_position, length);
+        _position += length;
+        return span;
+    }
+
+    public readonly Span<byte> AsSpan()
+    {
+        return _buffer.AsSpan();
+    }
+
+    public void Dispose()
+    {
+        _buffer.Dispose();
+    }
+}