Major refactor of graphics pipeline keying, shader cache, and resource allocation.
Replaced most Allocator usage with AllocationHandle, modernized logger usage,
and unified pipeline state keys. Updated MeshUtility to use AllocationHandle.FreeList.
Added new shader pipeline architecture docs and improved error handling throughout.
BREAKING CHANGE: Pipeline keying and resource allocation APIs have changed.
- 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.
