Fix item counts, PR/QT conversions, validation and department loss

app/po/manage_po.php

@@ -326,7 +326,7 @@
       </td>
       <td>
         <input type="number" class="form-control form-control-sm item_tax_rate"
-          value="${parseFloat(item.tax_rate || 0).toFixed(2)}" min="0" max="100" step="0.01" oninput="recalc_totals()">
+          value="${line_tax_rate(item).toFixed(2)}" min="0" max="100" step="0.01" oninput="recalc_totals()">
         <input type="hidden" class="item_tax_amount" value="${item.tax_amount || 0}">
       </td>
       <td class="item_total text-end">${format_number((item.quantity || 1) * (item.unit_price || 0), 2)}</td>
@@ -974,7 +974,7 @@
   // ── Boot ─────────────────────────────────────────────────────────────────
   $(async function() {
     try {
-      load_departments('department_id');
+      await Promise.resolve(load_departments('department_id')).catch(function() {});
       await load_location_config();
       await retrieve_warehouses();
 

app/po/po.php

@@ -226,8 +226,7 @@
     var body      = '';
 
     $.each(page_data, function(i, o) {
-      var items      = JSON.parse(o.items || '[]');
-      var item_count = items.length;
+      var item_count = parseInt(o.item_count) || 0;
       var can_cancel = parseInt(o.status) >= -2 && parseInt(o.status) <= 1;
 
       body += `<tr>

app/po/supplier_returns.php

@@ -218,9 +218,7 @@
     }
 
     $.each(rows, function(i, r) {
-      var items = [];
-      try { items = JSON.parse(r.items || '[]'); } catch(e) {}
-      var item_count = items.length;
+      var item_count = parseInt(r.item_count) || 0;
       body += `<tr>
         <td class="py-3 fw-semibold">${escape_html(r.return_number || '')}</td>
         <td class="py-3">