Fix parent names not using no separator

src/gaemstone/ECS/EntityBuilder.cs

@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using gaemstone.Utility;
 using static flecs_hub.flecs;
-using static flecs_hub.flecs.Runtime;
 
 namespace gaemstone.ECS;
 
@@ -79,7 +78,6 @@ public class EntityBuilder
 	public override EntityBuilder Set<T>(T obj)
 		{ _toSet.Add(e => e.Set(obj)); return this; }
 
-	public static CString ETX { get; } = (CString)"\x3";
 	public unsafe EntityRef Build()
 	{
 		var parent = _parent;
@@ -98,7 +96,7 @@ public class EntityBuilder
 			symbol     = alloc.AllocateCString(_symbol),
 			add_expr   = alloc.AllocateCString(Expression),
 			use_low_id = UseLowID,
-			sep        = ETX, // TODO: Replace with CStringExtensions.Empty once supported.
+			sep        = CStringExtensions.ETX,
 		};
 
 		var add = desc.add; var index = 0;

src/gaemstone/ECS/EntityPath.cs

@@ -124,7 +124,7 @@ public class EntityPath
 		foreach (var part in path)
 			fixed (byte* ptr = part.AsSpan())
 				if (skipLookup || (parent = new(ecs_lookup_child(universe, parent, ptr))).IsNone) {
-					var desc = new ecs_entity_desc_t { name = ptr };
+					var desc = new ecs_entity_desc_t { name = ptr, sep = CStringExtensions.ETX };
 					if (parent.IsSome) desc.add[0] = Identifier.Pair(universe.ChildOf, parent);
 					parent = new(ecs_entity_init(universe, &desc));
 					skipLookup = true;

src/gaemstone/Utility/CStringExtensions.cs

@@ -8,6 +8,7 @@ namespace gaemstone.Utility;
 public unsafe static class CStringExtensions
 {
 	public static CString Empty { get; } = (CString)"";
+	public static CString ETX { get; } = (CString)"\x3"; // TODO: Temporary, until flecs supports Empty.
 
 	public static unsafe byte[]? FlecsToBytes(this CString str)
 	{