feat: WebSocket presence tracking with page_focus and presence_update

Made-with: Cursor

backend/utils/websocket-manager.js

@@ -32,6 +32,8 @@ class WebSocketManager {
     const clientInfo = {
       authenticated: false,
       userId: null,
+      adminName: null,
+      currentPage: null,
       subscribedSessions: new Set(),
       lastPing: Date.now()
     };
@@ -96,6 +98,15 @@ class WebSocketManager {
         clientInfo.lastPing = Date.now();
         this.send(ws, { type: 'pong' });
         break;
+
+      case 'page_focus':
+        if (!clientInfo.authenticated) {
+          this.sendError(ws, 'Not authenticated');
+          return;
+        }
+        clientInfo.currentPage = message.page || null;
+        this.broadcastPresence();
+        break;
         
       default:
         this.sendError(ws, `Unknown message type: ${message.type}`);
@@ -117,7 +128,13 @@ class WebSocketManager {
       
       if (clientInfo) {
         clientInfo.authenticated = true;
-        clientInfo.userId = decoded.role; // 'admin' for now
+        clientInfo.userId = decoded.role;
+        clientInfo.adminName = decoded.name || null;
+
+        if (!decoded.name) {
+          this.sendError(ws, 'Token missing admin identity, please re-login', 'auth_error');
+          return;
+        }
         
         this.send(ws, {
           type: 'auth_success',
@@ -283,9 +300,31 @@ class WebSocketManager {
       
       this.clients.delete(ws);
       console.log('[WebSocket] Client disconnected and cleaned up');
+      this.broadcastPresence();
     }
   }
 
+  broadcastPresence() {
+    const admins = [];
+    this.clients.forEach((info) => {
+      if (info.authenticated && info.adminName && info.currentPage) {
+        admins.push({ name: info.adminName, page: info.currentPage });
+      }
+    });
+
+    const message = {
+      type: 'presence_update',
+      timestamp: new Date().toISOString(),
+      admins
+    };
+
+    this.clients.forEach((info, ws) => {
+      if (info.authenticated && ws.readyState === ws.OPEN) {
+        this.send(ws, message);
+      }
+    });
+  }
+
   /**
    * Start heartbeat to detect dead connections
    */