feat(config): agrega personalización de ticket con logo y opciones

- Nuevos endpoints /pos/api/config/receipt (GET/PUT)
- Sección en config.html para subir logo, datos del negocio y toggles visuales
- pos.js carga la config y renderiza el ticket usando logo, RFC, dirección,
  teléfono, mensajes y opciones de desglose/empleado/pago configurables
- Logo se redimensiona a 300px de ancho y se guarda como base64 JPEG en tenant_config

Tests: 35 passed

pos/static/js/config.js

@@ -443,6 +443,133 @@ const Config = (() => {
         }
     }
 
+    // -------------------------------------------------------------------------
+    // Receipt / ticket customization
+    // -------------------------------------------------------------------------
+    let _receiptLogo = '';
+
+    async function loadReceiptConfig() {
+        try {
+            var res = await fetch(API + '/receipt', { headers: headers() });
+            if (!res.ok) return;
+            var d = await res.json();
+            _receiptLogo = d.logo || '';
+            setVal('receipt-store-name', d.store_name);
+            setVal('receipt-tagline', d.tagline);
+            setVal('receipt-rfc', d.rfc);
+            setVal('receipt-address', d.address);
+            setVal('receipt-phone', d.phone);
+            setVal('receipt-thanks', d.thanks_message);
+            setVal('receipt-footer', d.footer);
+            setChecked('receipt-show-logo', d.show_logo);
+            setChecked('receipt-show-rfc', d.show_rfc);
+            setChecked('receipt-show-address', d.show_address);
+            setChecked('receipt-show-phone', d.show_phone);
+            setChecked('receipt-show-iva', d.show_iva_breakdown);
+            setChecked('receipt-show-payment', d.show_payment_details);
+            setChecked('receipt-show-employee', d.show_employee);
+            renderReceiptLogoThumb();
+        } catch (e) {
+            console.error('Config.loadReceiptConfig:', e);
+        }
+    }
+
+    function setChecked(id, v) {
+        var el = document.getElementById(id);
+        if (el) el.checked = !!v;
+    }
+
+    function getChecked(id) {
+        var el = document.getElementById(id);
+        return el ? el.checked : false;
+    }
+
+    function renderReceiptLogoThumb() {
+        var thumb = document.getElementById('receipt-logo-thumb');
+        var removeBtn = document.getElementById('receipt-logo-remove');
+        if (!thumb) return;
+        if (_receiptLogo) {
+            thumb.innerHTML = '<img src="' + escapeHtml(_receiptLogo) + '" style="max-width:100%;max-height:100%;object-fit:contain;" alt="Logo ticket">';
+            if (removeBtn) removeBtn.style.display = '';
+        } else {
+            thumb.innerHTML = '<span style="color:var(--color-text-muted);font-size:var(--text-caption);text-align:center;padding:var(--space-2);">Sin logo</span>';
+            if (removeBtn) removeBtn.style.display = 'none';
+        }
+    }
+
+    function handleReceiptLogo(input) {
+        var file = input && input.files ? input.files[0] : null;
+        if (!file) return;
+        if (!file.type.match(/^image\/(png|jpeg|jpg|webp)$/)) {
+            toast('Solo se permiten imágenes PNG, JPG o WebP', 'error');
+            input.value = '';
+            return;
+        }
+        var reader = new FileReader();
+        reader.onload = function(e) {
+            var img = new Image();
+            img.onload = function() {
+                var maxWidth = 300;
+                var scale = Math.min(1, maxWidth / img.width);
+                var w = Math.round(img.width * scale);
+                var h = Math.round(img.height * scale);
+                var canvas = document.createElement('canvas');
+                canvas.width = w;
+                canvas.height = h;
+                var ctx = canvas.getContext('2d');
+                ctx.fillStyle = '#ffffff';
+                ctx.fillRect(0, 0, w, h);
+                ctx.drawImage(img, 0, 0, w, h);
+                _receiptLogo = canvas.toDataURL('image/jpeg', 0.85);
+                renderReceiptLogoThumb();
+                toast('Logo cargado. Guarda los cambios para aplicarlo.', 'ok');
+            };
+            img.src = e.target.result;
+        };
+        reader.readAsDataURL(file);
+        input.value = '';
+    }
+
+    function removeReceiptLogo() {
+        _receiptLogo = '';
+        renderReceiptLogoThumb();
+    }
+
+    async function saveReceiptConfig() {
+        if (!checkAuth()) return;
+        var data = {
+            logo: _receiptLogo,
+            store_name: getVal('receipt-store-name'),
+            tagline: getVal('receipt-tagline'),
+            rfc: getVal('receipt-rfc'),
+            address: getVal('receipt-address'),
+            phone: getVal('receipt-phone'),
+            thanks_message: getVal('receipt-thanks'),
+            footer: getVal('receipt-footer'),
+            show_logo: getChecked('receipt-show-logo'),
+            show_rfc: getChecked('receipt-show-rfc'),
+            show_address: getChecked('receipt-show-address'),
+            show_phone: getChecked('receipt-show-phone'),
+            show_iva_breakdown: getChecked('receipt-show-iva'),
+            show_payment_details: getChecked('receipt-show-payment'),
+            show_employee: getChecked('receipt-show-employee'),
+        };
+        try {
+            var res = await fetch(API + '/receipt', {
+                method: 'PUT',
+                headers: headers(),
+                body: JSON.stringify(data),
+            });
+            if (!res.ok) {
+                var err = await res.json().catch(function() { return { error: res.statusText }; });
+                throw new Error(err.error || 'Error al guardar');
+            }
+            toast('Configuración de ticket guardada', 'ok');
+        } catch (e) {
+            toast(e.message, 'error');
+        }
+    }
+
     async function saveAll() {
         if (!checkAuth()) return;
         var btn = document.getElementById('btn-save-all');
@@ -454,6 +581,7 @@ const Config = (() => {
             await saveVehicleCompatSource();
             await saveAllowedBrands();
             await saveModules();
+            await saveReceiptConfig();
             toast('Configuración guardada', 'ok');
         } catch (e) {
             toast(e.message, 'error');
@@ -881,6 +1009,7 @@ const Config = (() => {
         loadVehicleCompatSource();
         loadAllowedBrands();
         loadModules();
+        loadReceiptConfig();
     }
 
     document.addEventListener('DOMContentLoaded', init);
@@ -900,6 +1029,7 @@ const Config = (() => {
         loadCurrency, saveCurrency,
         loadVehicleCompatSource, saveVehicleCompatSource,
         loadModules, saveModules,
+        loadReceiptConfig, saveReceiptConfig, handleReceiptLogo, removeReceiptLogo,
         openModal, closeModal, openBranchModal, editBranch
     };