Add CObjectTemplate marker interface for cache templates

ITEM, DEED and RUNE templates share one id space (JSON-Refactor-Plan D1).
Empty for now; the shared getters come with Task 1.1.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/parsers/objects/CObjectTemplate.java

@@ -0,0 +1,15 @@
+//  • ▌ ▄ ·.  ▄▄▄·  ▄▄ • ▪   ▄▄· ▄▄▄▄·  ▄▄▄·  ▐▄▄▄  ▄▄▄ .
+//  ·██ ▐███▪▐█ ▀█ ▐█ ▀ ▪██ ▐█ ▌▪▐█ ▀█▪▐█ ▀█ •█▌ ▐█▐▌·
+//  ▐█ ▌▐▌▐█·▄█▀▀█ ▄█ ▀█▄▐█·██ ▄▄▐█▀▀█▄▄█▀▀█ ▐█▐ ▐▌▐▀▀▀
+//  ██ ██▌▐█▌▐█ ▪▐▌▐█▄▪▐█▐█▌▐███▌██▄▪▐█▐█ ▪▐▌██▐ █▌▐█▄▄▌
+//  ▀▀  █▪▀▀▀ ▀  ▀ ·▀▀▀▀ ▀▀▀·▀▀▀ ·▀▀▀▀  ▀  ▀ ▀▀  █▪ ▀▀▀
+//      Magicbane Emulator Project © 2013 - 2026
+//                https://www.magicbane.com
+
+package engine.parsers.objects;
+
+// Common type for ITEM, DEED and RUNE cache templates, which share one id space.
+// Shared obj_/combat_/item_ getters arrive with JSON-Refactor-Plan Task 1.1.
+
+public interface CObjectTemplate {
+}

src/engine/parsers/objects/DeedTemplate.java

@@ -27,7 +27,7 @@ import java.util.LinkedHashMap;
 //
 // Read only once loaded.
 
-public class DeedTemplate {
+public class DeedTemplate implements CObjectTemplate {
 
     public static HashMap<Integer, DeedTemplate> _deeds = new HashMap<>();
 

src/engine/parsers/objects/ItemTemplate.java

@@ -29,7 +29,7 @@ import java.util.LinkedHashMap;
 // Not to be confused with engine.objects.ItemTemplate, which is loaded
 // from the database. Read only once loaded.
 
-public class ItemTemplate {
+public class ItemTemplate implements CObjectTemplate {
 
     public static HashMap<Integer, ItemTemplate> _items = new HashMap<>();
 

src/engine/parsers/objects/RuneTemplate.java

@@ -30,7 +30,7 @@ import java.util.LinkedHashMap;
 //
 // Read only once loaded.
 
-public class RuneTemplate {
+public class RuneTemplate implements CObjectTemplate {
 
     public static HashMap<Integer, RuneTemplate> _runes = new HashMap<>();