feat(buffer): add TLSF allocator and seqlock primitives

Added a TLSF (Two-Level Segregated Fit) memory allocator with O(1) allocation, free, and reallocation in `TLSF.cs`, plus comprehensive unit tests. Introduced a cache-line-padded `SeqLock` synchronization primitive. Refactored vector extension code for conciseness and fixed its usage to `extension(ref ...)`. Updated namespaces, removed unused code, and improved assertion and diagnostics. Updated NuGet dependencies and project files.

Misaki.HighPerformance.Test/UnitTest/Buffer/TestTlsfAllocator.cs

@@ -0,0 +1,76 @@
+using Misaki.HighPerformance.LowLevel.Buffer;
+
+namespace Misaki.HighPerformance.Test.UnitTest.Buffer;
+
+[TestClass]
+public class TestTlsfAllocator
+{
+    [TestMethod]
+    public unsafe void TestBasicAllocationAndFree()
+    {
+        using var allocator = TLSF.Create(new TLSF.CreationOptions { alignment = 16, initialChunkSize = 4096 });
+
+        var ptr1 = allocator.Allocate(100, 16);
+        Assert.IsTrue(ptr1 != null);
+
+        var ptr2 = allocator.Allocate(200, 16);
+        Assert.IsTrue(ptr2 != null);
+
+        allocator.Free(ptr1);
+        allocator.Free(ptr2);
+    }
+
+    [TestMethod]
+    public unsafe void TestReallocate()
+    {
+        using var allocator = TLSF.Create(new TLSF.CreationOptions { alignment = 16, initialChunkSize = 4096 });
+
+        var ptr = allocator.Allocate(100, 16);
+        Assert.IsTrue(ptr != null);
+
+        var newPtr = allocator.Reallocate(ptr, 100, 200, 16);
+        Assert.IsTrue(newPtr != null);
+
+        allocator.Free(newPtr);
+    }
+
+    [TestMethod]
+    public unsafe void TestMemoryPoolIntegration()
+    {
+        using var pool = new MemoryPool<TLSF, TLSF.CreationOptions>(new TLSF.CreationOptions { alignment = 16 });
+
+        var ptr2 = pool.Allocator.Allocate(50, 16);
+        Assert.IsTrue(ptr2 != null);
+        pool.Allocator.Free(ptr2);
+    }
+
+    [TestMethod]
+    public unsafe void TestLargeAllocation()
+    {
+        using var allocator = TLSF.Create(new TLSF.CreationOptions { alignment = 16, initialChunkSize = 4096 });
+
+        // This should force the allocator to allocate a new chunk
+        var ptr = allocator.Allocate(1024 * 1024, 16);
+        Assert.IsTrue(ptr != null);
+        allocator.Free(ptr);
+    }
+
+    [TestMethod]
+    public unsafe void TestMultipleAllocations()
+    {
+        using var allocator = TLSF.Create(new TLSF.CreationOptions { alignment = 16, initialChunkSize = 4096 });
+
+        var ptrs = stackalloc void*[100];
+
+        for (var i = 0; i < 100; i++)
+        {
+            ptrs[i] = allocator.Allocate((nuint)(i * 10 + 16), 16);
+            Assert.IsTrue(ptrs[i] != null);
+        }
+
+        for (var i = 0; i < 100; i++)
+        {
+            allocator.Free(ptrs[i]);
+        }
+    }
+}