feat(pos): integrate design system for facturacion, contabilidad, dashboard, config, reportes

Replace 5 POS templates with updated design system pages using tokens.css.
Add routes for dashboard, config, and reports pages.
Create stub JS files for dashboard, config, and reports modules.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pos/static/js/reports.js

@@ -0,0 +1,99 @@
+// /home/Autopartes/pos/static/js/reports.js
+// Reports module: sales reports, inventory reports, financial reports
+
+const Reports = (() => {
+    function token() {
+        return localStorage.getItem('pos_token') || '';
+    }
+
+    function checkAuth() {
+        if (!token()) {
+            window.location.href = '/pos/login';
+            return false;
+        }
+        return true;
+    }
+
+    function headers() {
+        return { 'Authorization': `Bearer ${token()}`, 'Content-Type': 'application/json' };
+    }
+
+    function fmt(n) {
+        return parseFloat(n || 0).toLocaleString('es-MX', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
+    }
+
+    // -------------------------------------------------------------------------
+    // Theme switcher
+    // -------------------------------------------------------------------------
+    function setTheme(theme) {
+        document.documentElement.setAttribute('data-theme', theme);
+        try { localStorage.setItem('nexus-theme', theme); } catch(e) {}
+        var btnInd = document.getElementById('btn-industrial');
+        var btnMod = document.getElementById('btn-modern');
+        if (btnInd) btnInd.classList.toggle('is-active', theme === 'industrial');
+        if (btnMod) btnMod.classList.toggle('is-active', theme === 'modern');
+    }
+    window.setTheme = setTheme;
+
+    // -------------------------------------------------------------------------
+    // Tab switcher
+    // -------------------------------------------------------------------------
+    function switchTab(id, btn) {
+        document.querySelectorAll('.tab-panel').forEach(function(p) { p.classList.remove('is-active'); });
+        document.querySelectorAll('.tab-btn').forEach(function(b) { b.classList.remove('is-active'); });
+        var panel = document.getElementById('panel-' + id);
+        if (panel) panel.classList.add('is-active');
+        if (btn) btn.classList.add('is-active');
+    }
+    window.switchTab = switchTab;
+
+    // -------------------------------------------------------------------------
+    // Live clock
+    // -------------------------------------------------------------------------
+    function updateClock() {
+        var el = document.getElementById('live-clock');
+        if (!el) return;
+        var now = new Date();
+        var pad = function(n) { return String(n).padStart(2, '0'); };
+        el.textContent = pad(now.getHours()) + ':' + pad(now.getMinutes()) + ':' + pad(now.getSeconds());
+    }
+
+    // -------------------------------------------------------------------------
+    // Placeholder API calls
+    // -------------------------------------------------------------------------
+    async function loadSalesReport(params) {
+        // TODO: call /pos/api/cashregister/... with date range
+    }
+
+    async function loadInventoryReport() {
+        // TODO: call /pos/api/inventory/products for stock report
+    }
+
+    async function loadFinancialReport(params) {
+        // TODO: call /pos/api/accounting/... for financial reports
+    }
+
+    // -------------------------------------------------------------------------
+    // Init
+    // -------------------------------------------------------------------------
+    function init() {
+        if (!checkAuth()) return;
+
+        // Restore theme
+        try {
+            var saved = localStorage.getItem('nexus-theme') || 'industrial';
+            setTheme(saved);
+        } catch(e) {}
+
+        // Start clock
+        updateClock();
+        setInterval(updateClock, 1000);
+    }
+
+    document.addEventListener('DOMContentLoaded', init);
+
+    return {
+        init, setTheme, switchTab,
+        loadSalesReport, loadInventoryReport, loadFinancialReport, fmt
+    };
+})();