feat(ui): infinite scroll, saved filters, product timeline, image comparator, customers bulk toolbar, dark mode refinements

pos/static/js/customers.js

@@ -94,6 +94,8 @@ const Customers = (() => {
         }
     }
 
+    var selectedCustomers = new Set();
+
     function renderCustomerRow(c) {
         const tier = tierMap[c.price_tier] || 'Mostrador';
         const tClass = tierClass[c.price_tier] || 'mostrador';
@@ -104,7 +106,9 @@ const Customers = (() => {
         const creditClass = usedPct >= 80 ? 'none' : usedPct >= 60 ? 'low' : '';
         const num = String(c.id).padStart(5, '0');
         const selClass = (currentCustomer && currentCustomer.id === c.id) ? 'selected' : '';
-        return '<tr class="' + selClass + '" onclick="Customers.selectCustomer(' + c.id + ')">' +
+        const isChecked = selectedCustomers.has(c.id) ? 'checked' : '';
+        return '<tr class="' + selClass + '">' +
+            '<td onclick="event.stopPropagation();"><input type="checkbox" ' + isChecked + ' onchange="Customers.toggleCustomerSelection(' + c.id + ')"></td>' +
             '<td class="cell-num">' + num + '</td>' +
             '<td>' +
                 '<div class="cell-name">' + (c.name || '') + '</div>' +
@@ -801,6 +805,41 @@ const Customers = (() => {
         showPaymentModal, closePayment, recordPayment,
     };
 
+    // Bulk selection
+    publicApi.toggleCustomerSelection = function(id) {
+        if (selectedCustomers.has(id)) selectedCustomers.delete(id);
+        else selectedCustomers.add(id);
+        updateBulkToolbar();
+    };
+    publicApi.toggleSelectAll = function() {
+        var cb = document.getElementById('selectAllCustomers');
+        var allChecked = cb.checked;
+        if (customersVS && customersVS.data) {
+            customersVS.data.forEach(function(c) {
+                if (allChecked) selectedCustomers.add(c.id);
+                else selectedCustomers.delete(c.id);
+            });
+            customersVS.refresh();
+        }
+        updateBulkToolbar();
+    };
+    function updateBulkToolbar() {
+        var container = document.getElementById('customersBulkToolbar');
+        if (!container) return;
+        var count = selectedCustomers.size;
+        if (count === 0) { container.innerHTML = ''; return; }
+        container.innerHTML = renderBulkToolbar(count,
+            '<button class="btn btn--primary btn--sm" onclick="Customers.featureProximamente(\'Exportar seleccionados\')">📥 Exportar</button>' +
+            '<button class="btn btn--ghost btn--sm" onclick="Customers.clearSelection()">Limpiar</button>'
+        );
+    }
+    publicApi.clearSelection = function() {
+        selectedCustomers.clear();
+        document.getElementById('selectAllCustomers').checked = false;
+        if (customersVS) customersVS.refresh();
+        updateBulkToolbar();
+    };
+
     // Expose globally for inline HTML onclick handlers
     window.Customers = publicApi;
     return publicApi;