feat(buffer): add allocation tracking and diagnostics

Add AllocationManager.GetTotalAllocatedMemory() to track total allocations when safety checks are enabled. Improve diagnostics by calling Debug.Fail in Dispose methods of HashMapHelper, UnTypedArray, and UnsafeArray when disposing uninitialized or already disposed arrays. Remove AddRange(ReadOnlyUnsafeCollection<T>) from UnsafeList<T>. Increment assembly version to 1.6.4. Ensure arrcpy is disposed in Program.cs.

Misaki.HighPerformance.LowLevel/Buffer/AllocationManager.cs

@@ -1,5 +1,7 @@
 #if MHP_ENABLE_SAFETY_CHECKS
 using Misaki.HighPerformance.Collections;
+using System.Collections.Concurrent;
+
 #endif
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
@@ -804,6 +806,30 @@ public static unsafe class AllocationManager
 #endif
     }
 
+    /// <summary>
+    /// Gets the total newSize of all currently tracked allocations.
+    /// </summary>
+    /// <remarks>
+    /// Always returns 0 if MHP_ENABLE_SAFETY_CHECKS is disabled.
+    /// </remarks>
+    /// <returns>The total newSize of all currently tracked allocations.</returns>
+    public static nuint GetTotalAllocatedMemory()
+    {
+#if MHP_ENABLE_SAFETY_CHECKS
+        Debug.Assert(s_initialized, "AllocationManager is not initialized.");
+        
+        nuint total = 0;
+        foreach (var allocation in s_allocations)
+        {
+            total += allocation.Size;
+        }
+
+        return total;
+#else
+        return 0;
+#endif
+    }
+
     /// <summary>
     /// Disposes of the AllocationManager, freeing all allocated memory and resources.
     /// </summary>