🩹 Ensure invalid root type for initial context buffer rental

Author: andersstorhaug

Lite3DotNet/Lite3Context.cs

@@ -25,7 +25,8 @@ public static Lite3Context Create(int initialCapacity = Lite3Buffer.MinBufferSiz
 
         var buffer = arrayPool.Rent(initialCapacity);
 
-        buffer.AsSpan().Clear();
+        // Ensure that at least the root type tag is invalid
+        buffer[0] = (byte)Lite3Core.ValueKind.Invalid;
 
         return new  Lite3Context(buffer, position: 0, isRentedBuffer: true, arrayPool);
     }