Add size-in-label checkbox to battery add form

templates/battery_add.html

@@ -27,6 +27,12 @@
         <label for="count">Quantity</label>
         <input type="number" id="count" name="count" value="{{ form_count|default(1) }}" min="1" max="50">
         <small class="text-muted">Labels are auto-generated (e.g. Eneloop 001, Eneloop 002)</small>
+        <div style="margin-top:0.4rem;">
+          <label style="display:inline-flex;align-items:center;gap:0.4rem;font-weight:normal;cursor:pointer;">
+            <input type="checkbox" id="include_size_in_label" name="include_size_in_label">
+            Include size in label (e.g. Eneloop AAA 001)
+          </label>
+        </div>
         <div id="label-preview" style="font-size:0.85rem;color:var(--link);margin-top:0.3rem;font-weight:500;min-height:1.2em;"></div>
       </div>
 
@@ -97,7 +103,7 @@
 </div>
 
 <script>
-var brandCounts = {{ brand_counts|default({})|tojson }};
+var prefixMaxNums = {{ prefix_max_nums|default({})|tojson }};
 
 function metaSelectChanged(sel, inputId) {
   var input = document.getElementById(inputId);
@@ -109,25 +115,30 @@ function metaSelectChanged(sel, inputId) {
     input.style.display = 'none';
     input.value = sel.value;
   }
-  if (inputId === 'brand') updateLabelPreview();
+  if (inputId === 'brand' || inputId === 'size') updateLabelPreview();
 }
 
 function updateLabelPreview() {
   var brand = document.getElementById('brand').value.trim();
+  var size  = document.getElementById('size').value.trim();
+  var includeSize = document.getElementById('include_size_in_label').checked;
   var count = parseInt(document.getElementById('count').value, 10) || 1;
   var preview = document.getElementById('label-preview');
   if (!brand) { preview.textContent = ''; return; }
-  var existing = brandCounts[brand] !== undefined ? brandCounts[brand] : 0;
+  var prefix = (includeSize && size) ? brand + ' ' + size : brand;
+  var existing = prefixMaxNums[prefix] !== undefined ? prefixMaxNums[prefix] : 0;
   var first = existing + 1;
   var last  = existing + count;
   var pad = function(n) { return n.toString().padStart(3, '0'); };
   preview.textContent = count === 1
-    ? 'Will create: ' + brand + ' ' + pad(first)
-    : 'Will create: ' + brand + ' ' + pad(first) + ' \u2192 ' + brand + ' ' + pad(last);
+    ? 'Will create: ' + prefix + ' ' + pad(first)
+    : 'Will create: ' + prefix + ' ' + pad(first) + ' \u2192 ' + prefix + ' ' + pad(last);
 }
 
 document.getElementById('count').addEventListener('input', updateLabelPreview);
 document.getElementById('brand').addEventListener('input', updateLabelPreview);
+document.getElementById('size').addEventListener('input', updateLabelPreview);
+document.getElementById('include_size_in_label').addEventListener('change', updateLabelPreview);
 
 // Restore brand state on error re-render
 (function () {