fix: chart.js legend error + smart cache for date-range queries

- Fix forecast chart confidence band fill config (fill:'+1' → explicit target)
  to resolve 't.legend.handleEvent' TypeError in Chart.js 4.4.1
- Add getOrFetchRange() to cache.js: auto TTL based on data age
  (end date >10 days old → 24h cache, recent → 5min cache)
- Apply smart cache to 6 heavy endpoints: bi, bi/revenue, bi/strategic,
  providers, providers/failed, providers/trend

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server.js

@@ -357,7 +357,7 @@ app.get('/admin/api/bi', requireRole('admin'), async (req, res) => {
       return row ? row.nome : null;
     };
 
-    const data = await fetchBIData(start, end, getAgenteName);
+    const data = await cache.getOrFetchRange('bi', start, end, () => fetchBIData(start, end, getAgenteName));
     res.json(data);
   } catch (err) {
     console.error('Admin BI API error:', err);
@@ -369,7 +369,8 @@ app.get('/admin/api/bi/revenue', requireRole('admin'), async (req, res) => {
   try {
     const { start, end, granularity } = req.query;
     if (!start || !end) return res.status(400).json({ error: 'start and end required' });
-    const data = await fetchRevenueAnalytics(start, end, granularity || 'dia');
+    const g = granularity || 'dia';
+    const data = await cache.getOrFetchRange(`bi-rev-${g}`, start, end, () => fetchRevenueAnalytics(start, end, g));
     res.json(data);
   } catch (err) {
     console.error('Revenue API error:', err);
@@ -381,7 +382,7 @@ app.get('/admin/api/bi/strategic', requireRole('admin'), async (req, res) => {
   try {
     const { start, end } = req.query;
     if (!start || !end) return res.status(400).json({ error: 'start and end required' });
-    const data = await fetchBIStrategic(start, end);
+    const data = await cache.getOrFetchRange('bi-strat', start, end, () => fetchBIStrategic(start, end));
     res.json(data);
   } catch (err) {
     console.error('Strategic BI API error:', err);
@@ -917,7 +918,7 @@ app.get('/admin/api/providers', requireRole('admin'), async (req, res) => {
   try {
     const { start, end } = req.query;
     if (!start || !end) return res.status(400).json({ error: 'start and end required' });
-    const data = await fetchProviderPerformance(start, end);
+    const data = await cache.getOrFetchRange('providers', start, end, () => fetchProviderPerformance(start, end));
     res.json(data);
   } catch (err) {
     console.error('Provider API error:', err);
@@ -929,7 +930,7 @@ app.get('/admin/api/providers/failed', requireRole('admin'), async (req, res) =>
   try {
     const { start, end } = req.query;
     if (!start || !end) return res.status(400).json({ error: 'start and end required' });
-    const data = await fetchFailedTransactions(start, end);
+    const data = await cache.getOrFetchRange('providers-fail', start, end, () => fetchFailedTransactions(start, end));
     res.json(data);
   } catch (err) {
     console.error('Failed TX API error:', err);
@@ -941,7 +942,7 @@ app.get('/admin/api/providers/trend', requireRole('admin'), async (req, res) =>
   try {
     const { start, end } = req.query;
     if (!start || !end) return res.status(400).json({ error: 'start and end required' });
-    const data = await fetchProviderTrend(start, end);
+    const data = await cache.getOrFetchRange('providers-trend', start, end, () => fetchProviderTrend(start, end));
     res.json(data);
   } catch (err) {
     console.error('Provider Trend API error:', err);

src/admin-bi.js

@@ -2142,15 +2142,19 @@ async function loadForecast() {
       data: {
         labels: allLabels,
         datasets: [
-          { label: 'Historical', data: histFull, borderColor: theme.blue, backgroundColor: 'transparent', borderWidth: 2, pointRadius: 0, tension: 0.3 },
-          { label: 'Forecast', data: predValues, borderColor: theme.green, backgroundColor: 'transparent', borderWidth: 2, borderDash: [6,3], pointRadius: 0, tension: 0.3 },
-          { label: 'Upper 95%', data: upperValues, borderColor: 'transparent', backgroundColor: theme.green + '15', fill: '+1', pointRadius: 0 },
-          { label: 'Lower 95%', data: lowerValues, borderColor: 'transparent', backgroundColor: 'transparent', fill: false, pointRadius: 0 }
+          { label: 'Confidence 95%', data: upperValues, borderColor: 'transparent', backgroundColor: theme.green + '15', fill: { target: 3, above: theme.green + '15' }, pointRadius: 0, tension: 0.3 },
+          { label: 'Historical', data: histFull, borderColor: theme.blue, backgroundColor: 'transparent', borderWidth: 2, pointRadius: 0, tension: 0.3, fill: false },
+          { label: 'Forecast', data: predValues, borderColor: theme.green, backgroundColor: 'transparent', borderWidth: 2, borderDash: [6,3], pointRadius: 0, tension: 0.3, fill: false },
+          { data: lowerValues, borderColor: 'transparent', backgroundColor: 'transparent', pointRadius: 0, tension: 0.3, fill: false }
         ]
       },
       options: {
         responsive: true, maintainAspectRatio: false,
-        plugins: { legend: { position: 'top', labels: { color: theme.text, usePointStyle: true, pointStyle: 'line', font: { size: 11 } } } },
+        plugins: {
+          legend: { position: 'top', labels: { color: theme.text, usePointStyle: true, pointStyle: 'line', font: { size: 11 }, filter: function(item) { return item.text !== undefined; } } },
+          tooltip: { filter: function(item) { return item.dataset.label !== undefined; } },
+          filler: { propagate: false }
+        },
         scales: {
           x: { ticks: { color: theme.text, maxTicksLimit: 15, font: { size: 10 } }, grid: { color: theme.grid } },
           y: { ticks: { color: theme.text, callback: function(v){return '$' + (v>=1000 ? Math.round(v/1000)+'K' : v);} }, grid: { color: theme.grid } }

src/cache.js

@@ -132,6 +132,32 @@ async function getOrFetch(key, fetchFn, ttl = DEFAULT_TTL) {
   return value;
 }
 
+/**
+ * Smart TTL para queries com date range:
+ * - end date > 10 dias atrás → dados imutáveis → TTL 24h
+ * - end date recente → dados mudam → TTL curto (5 min)
+ */
+const IMMUTABLE_TTL = 24 * 60 * 60 * 1000; // 24h
+const FRESH_TTL = 5 * 60 * 1000; // 5 min
+const STALE_DAYS = 10;
+
+function getDateRangeTTL(endDate) {
+  const end = new Date(endDate + 'T23:59:59');
+  const cutoff = new Date();
+  cutoff.setDate(cutoff.getDate() - STALE_DAYS);
+  return end < cutoff ? IMMUTABLE_TTL : FRESH_TTL;
+}
+
+/**
+ * Cache-aware fetch para queries com date range.
+ * Key = prefix + start + end. TTL automático baseado na idade dos dados.
+ */
+async function getOrFetchRange(prefix, start, end, fetchFn) {
+  const key = `${prefix}:${start}:${end}`;
+  const ttl = getDateRangeTTL(end);
+  return getOrFetch(key, fetchFn, ttl);
+}
+
 /**
  * Stats do cache
  */
@@ -160,5 +186,7 @@ module.exports = {
   clear,
   registerAutoRefresh,
   getOrFetch,
+  getOrFetchRange,
+  getDateRangeTTL,
   stats
 };