maint: clean-up of some combat related classes and methods for clarity

Assets/Scripts/Units/IKillable.cs

@@ -1,5 +1,6 @@
 using Drawing;
 using Reset.Core;
+using Unity.Netcode;
 using UnityEngine;
 
 namespace Reset.Units{
@@ -21,6 +22,9 @@ namespace Reset.Units{
                 currentHealth = maxHealth;
             }
         }
+        
+        [Rpc(SendTo.Everyone)]
+        void SetHealthRpc(float health);
 
         internal void DrawHealthDebug(){
             using (Draw.WithColor(Color.blue)) {