feat: implement consistent 20-color mapping for visible products across dashboard charts

backend/index.js

@@ -61,6 +61,25 @@ const verifyToken = (req, res, next) => {
     });
 };
 
+const sseClients = new Set();
+
+// SSE Endpoint for real-time updates
+app.get('/api/stream', (req, res) => {
+    res.setHeader('Content-Type', 'text/event-stream');
+    res.setHeader('Cache-Control', 'no-cache');
+    res.setHeader('Connection', 'keep-alive');
+    res.flushHeaders();
+
+    // Send initial connection event
+    res.write('data: {"connected": true}\n\n');
+
+    sseClients.add(res);
+
+    req.on('close', () => {
+        sseClients.delete(res);
+    });
+});
+
 // Login Endpoint
 app.post('/api/login', (req, res) => {
     const { email, password } = req.body;