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.
Introduced RenderExtractionSystem for entity-based render data extraction. Added MeshInstance and MeshPalette components with shadow casting support. Refactored QueryBuilder API, SharedComponentStore, and component registration for clarity and flexibility. Updated SystemManager and SystemGroup to use SystemAPI. Replaced RenderingConfig with GraphicsEngineDesc/RenderSystemDesc. RenderFrame now uses CPU/GPU fence values for sync. Removed Camera.cs in favor of ECS-based rendering. Improved Material, RenderingLayerMask, Mesh, and RenderList APIs. Updated package references and fixed naming, error handling, and disposal issues.
