Add cleanup for ref

demo/src/ReplicatedStorage/std/components.luau

@@ -8,8 +8,9 @@ local components: {
     Model: Entity<Model>,
     Player: Entity,
     Target: Entity,
-    Transform: Entity<{ old: CFrame, new: CFrame }>,
+    Transform: Entity<CFrame>,
     Velocity: Entity<number>,
+    Previous: Entity,
 } = {
     Character = world:component(),
     Mob = world:component(),
@@ -18,6 +19,7 @@ local components: {
     Target = world:component(),
     Transform = world:component(),
     Velocity = world:component(),
+    Previous = world:component(),
 }
 
 return table.freeze(components)

demo/src/ReplicatedStorage/std/ref.luau

@@ -2,7 +2,13 @@ local world = require(script.Parent.world)
 local handle = require(script.Parent.handle)
 local refs = {}
 
-local function ref(key)
+local function fini(e, key)
+    return function()
+        refs[key] = nil
+    end
+end
+
+local function ref(key): (handle.Handle, (() -> ())?)
     if not key then
         return handle(world:entity())
     end
@@ -12,7 +18,7 @@ local function ref(key)
         refs[key] = e
     end
     -- Cannot cache handles because they will get invalidated
-    return handle(e)
+    return handle(e), fini(e, key)
 end
 
 return ref