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>

src/App.tsx

@@ -422,11 +422,12 @@ function App() {
   const fetchData = useCallback(async () => {
     setRefreshing(true)
     try {
-      const response = await fetch('/api.php')
+      const response = await fetch('/api/dashboard')
       if (!response.ok) throw new Error('Failed to fetch')
       const json = await response.json()
       setData(json)
-    } catch {
+    } catch (error) {
+      console.error('Failed to fetch dashboard data:', error)
       setData(getMockData())
     } finally {
       setLoading(false)