feat: add Node.js/Express API with real data from Desk CRM

- ✅ API completa em /api com TypeScript
- ✅ Google Calendar integration (pessoal + profissional)
- ✅ Queries diretas à BD: tasks, leads, projectos, billing, pipeline
- ✅ Endpoints: /api/dashboard, /api/monitor, /api/health
- ✅ Vite proxy configurado (/api → localhost:3001)
- ✅ App.tsx usa /api/dashboard (não mais dados mock)
- ✅ Migração completa do PHP (index.php + monitor.php)
- ✅ CHANGELOG.md criado para tracking
- ✅ Scripts npm: dev (paralelo), dev:api, dev:ui, start

Dependencies:
- express, cors, mysql2, googleapis
- concurrently, tsx (dev)

Breaking: PHP backend será descontinuado
See: CHANGELOG.md, api/README.md

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

api/db.ts

@@ -0,0 +1,32 @@
+/**
+ * Database Connection Pool
+ * @author Descomplicar® | @link descomplicar.pt | @copyright 2026
+ */
+import mysql from 'mysql2/promise'
+
+// Database configuration
+const config = {
+  host: process.env.DB_HOST || 'localhost',
+  user: process.env.DB_USER || 'ealmeida_desk24',
+  password: process.env.DB_PASS || '9qPRdCGGqM4o',
+  database: process.env.DB_NAME || 'ealmeida_desk24',
+  waitForConnections: true,
+  connectionLimit: 10,
+  queueLimit: 0,
+  charset: 'utf8mb4'
+}
+
+// Create connection pool
+const pool = mysql.createPool(config)
+
+// Test connection
+pool.getConnection()
+  .then(conn => {
+    console.log('✅ MySQL connected')
+    conn.release()
+  })
+  .catch(err => {
+    console.error('❌ MySQL connection error:', err.message)
+  })
+
+export default pool