Merge AMS unit labels

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

public/app.js

@@ -2450,7 +2450,15 @@ function slotLabel(slot) {
   const p = printerList.find((x) => x.serial === serial);
   const name = p ? printerName(p) : '';
   if (unit === 'ext') return name ? `on the ${name}’s external holder` : 'on the external holder';
-  return `in ${name ? `${name}, ` : ''}AMS ${Number(unit) + 1}, slot ${Number(idx) + 1}`;
+  return `in ${name ? `${name}, ` : ''}${amsUnitLabel(Number(unit))}, slot ${Number(idx) + 1}`;
+}
+
+// Printers number AMS units in ranges: 0–15 for an AMS or AMS 2 Pro, 128 and up
+// for an AMS HT, and newer printers (the A2L, for one) put an AMS lite at 16.
+function amsUnitLabel(id) {
+  if (id >= 128) return `AMS HT ${id - 127}`;
+  if (id >= 16) return `AMS ${id - 15}`;
+  return `AMS ${id + 1}`;
 }
 
 function spoolHtml(s) {