new battle gui

src/BattleSetCoreAction.cs

@@ -0,0 +1,40 @@
+using Cthangover.Core.Actions;
+
+namespace Cthangover.Core.Battle
+{
+    /// <summary>
+    /// Selects which battle core (combat ruleset) the next battle will use.
+    /// The "core" variable maps to a <see cref="BattleCoreRegistry"/> entry by
+    /// string ID. Must be called before a battle starts, as
+    /// <see cref="BattleService.Init"/> reads the active core at initialization time.
+    /// </summary>
+    public class BattleSetCoreAction : IScenarioAction
+    {
+        /// <summary>
+        /// Registered as "battle.set_core" — selects the combat ruleset
+        /// for the next battle encounter. If "core" is empty or missing, logs a
+        /// warning and returns without modifying the registry.
+        /// </summary>
+        public string Name => "battle.set_core";
+
+        /// <summary>
+        /// Reads the "core" variable and sets it as the active battle core
+        /// via <see cref="BattleCoreRegistry.SetActive"/>. The core determines
+        /// combat mechanics (turn order, ability system, etc.) for the
+        /// next initiated battle.
+        /// </summary>
+        public void Run(IActionContext ctx)
+        {
+            var core = ctx.GetParam("core");
+            if (string.IsNullOrEmpty(core))
+            {
+                ctx.Log("EVENT", "BattleSetCoreAction: missing 'core' variable");
+                return;
+            }
+
+            BattleCoreRegistry.Instance.SetActive(core);
+            ctx.Log("EVENT", $"BattleSetCoreAction: battle core set to '{core}'");
+        }
+    }
+}
+