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 {
+}