Add ITEM cache JSON parser

ItemTemplate follows ArcItemTemplate_Load (sb.exe 0x4AABD0): weapon and
armor blocks keyed by item type, sheath and stub blocks, and empty equip
slot masks read as empty sets. Adds SheathSlot and readHashLabel, which
keeps unresolved hashes such as item_skill_used in 195340.

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

src/engine/parsers/cache/CacheParserUtil.java

@@ -227,6 +227,27 @@ public class CacheParserUtil {
         return "";
     }
 
+    // Like readLabel, but a non-zero number is a hash the exporter could not
+    // name; it is kept as its decimal string rather than dropped.
+
+    public static String readHashLabel(JSONObject json, String key, int templateId) {
+
+        Object value = json.get(key);
+        long hash;
+
+        if (value instanceof String)
+            return (String) value;
+
+        hash = json.getLong(key);
+
+        if (hash == 0)
+            return "";
+
+        Logger.warn(templateId + ": " + key + " has unresolved hash " + hash);
+
+        return Long.toString(hash);
+    }
+
     public static ArrayList<UserPowerAction> readUserPowerActions(JSONArray actionsJson) {
 
         ArrayList<UserPowerAction> userPowerActions = new ArrayList<>();