Move the vendor mod table off the legacy item template

LOAD_TEMPLATE_MODTABLES now returns a templateID -> modTable map that
ForgeManager owns (vendorModTables). ForgeManager.forgeItem, WorkOrder
validation and the ManageNPCMsg forge item list read it through
ForgeManager.getVendorModTable(), and ItemTemplate.modTable is removed.

Values are unchanged: static_vendor_items has 5089 rows, one per
templateID, all present in static_item_templates, modTable 0-30.
Templates not in the table still read 0. The old loader stopped at the
first templateID missing from ItemTemplate.templates; there are none.
No comparator added or removed.

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

src/engine/loot/WorkOrder.java

@@ -136,7 +136,7 @@ public class WorkOrder implements Delayed {
             return 30;  //30: That person cannot carry that item
 
         if ((workOrder.prefixToken != 0 || workOrder.suffixToken != 0) &&
-                !workOrder.vendor.getItemModTable().contains((template.modTable)))
+                !workOrder.vendor.getItemModTable().contains(ForgeManager.getVendorModTable(workOrder.templateID)))
             return 59;   //59: This hireling does not have this formula
 
         if (!Warehouse.calcCostOverrun(workOrder).isEmpty())