feat: replace SSE with Grafana-style client polling and rich date presets

backend/index.js

@@ -61,32 +61,6 @@ 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.setHeader('X-Accel-Buffering', 'no'); // Bypass Nginx Proxy Manager buffering
-    res.flushHeaders();
-
-    // Send initial connection event
-    res.write('data: {"connected": true}\n\n');
-
-    // Keep connection alive through Nginx/Cloudflare
-    const keepAlive = setInterval(() => {
-        res.write(':\n\n'); // SSE comment to prevent idle timeout
-    }, 15000);
-
-    sseClients.add(res);
-
-    req.on('close', () => {
-        clearInterval(keepAlive);
-        sseClients.delete(res);
-    });
-});
-
 // Login Endpoint
 app.post('/api/login', (req, res) => {
     const { email, password } = req.body;
@@ -169,12 +143,6 @@ app.post('/api/data', authenticateAPIKey, async (req, res) => {
             }
             
             await client.query('COMMIT');
-            
-            // Broadcast update to all connected SSE clients
-            const broadcastMessage = `data: {"type": "update"}\n\n`;
-            for (const clientRes of sseClients) {
-                clientRes.write(broadcastMessage);
-            }
         } catch (error) {
             await client.query('ROLLBACK');
             console.error("Database insert error:", error);