Refactor allocation flags, SPMD API, and cleanup

Replaced HasFlag with HasOption for allocation flags to avoid boxing and improve performance. Added AllocationOptionExtensions. Reduced FreeListChunkSize default. Removed redundant allocation handle checks. Renamed MultipleAdd to MultiplyAdd in SPMD interfaces and implementations, updating all usages. Expanded SPMD lane interface with new mask/scatter methods and XML docs. Updated GGX jobs and allocation tests. Bumped assembly versions.

Misaki.HighPerformance.LowLevel/Buffer/MemoryBlock.cs

@@ -42,13 +42,6 @@ public unsafe struct MemoryBlock : IDisposable
 
     public MemoryBlock(nuint size, nuint alignment, AllocationHandle handle, AllocationOption allocationOption = AllocationOption.None)
     {
-        ArgumentOutOfRangeException.ThrowIfNegative(size);
-
-        if (handle.Alloc == null)
-        {
-            throw new InvalidOperationException("Target allocation handle does not support allocation.");
-        }
-
         _buffer = handle.Alloc(size, alignment, allocationOption);
         _size = size;
         _alignment = alignment;