fix: remove hardcoded VITE_API_URL and adjust socket connection logic

The VITE_API_URL environment variable was being hardcoded in the infrastructure script, which is unnecessary for production. The frontend socket connection logic has been updated to use a relative path ('/') in production while maintaining localhost for development. This ensures proper WebSocket connections in both environments without requiring explicit backend URLs in production.

Author: christopherldo

apps/infra/index.ts

@@ -106,7 +106,6 @@ cd /home/ec2-user/app
 cat <<EOT >> .env
 NODE_ENV=production
 REDIS_URL=redis://${redisHost}:6379
-VITE_API_URL=http://localhost:3000
 EOT
 
 chown -R ec2-user:ec2-user /home/ec2-user/app

apps/web/src/pages/OverlayPage.spec.tsx

@@ -30,7 +30,7 @@ describe('OverlayPage', () => {
       </MemoryRouter>
     );
 
-    const mSocket = io('http://localhost');
+    const mSocket = io('/');
     expect(io).toHaveBeenCalled();
 
     // Simulate connect event

apps/web/src/pages/OverlayPage.tsx

@@ -62,7 +62,7 @@ export function OverlayPage() {
     if (!channel) return;
 
     // Connect to WebSocket (relative if same domain, or specify backend URL in dev)
-    const socketUrl = import.meta.env.VITE_API_URL || 'http://localhost:3000';
+    const socketUrl = import.meta.env.VITE_API_URL || (import.meta.env.DEV ? 'http://localhost:3000' : '/');
     const socket = io(socketUrl);
     socketRef.current = socket;