Refactor API configuration and improve WebSocket handling in frontend and backend

frontend/src/config/index.ts

@@ -0,0 +1,24 @@
+interface Config {
+  apiUrl: string;
+  wsUrl: string;
+  environment: 'development' | 'production';
+}
+
+function loadConfig(): Config {
+  const apiUrl = import.meta.env.VITE_API_URL || 'http://localhost:8080/api';
+  const wsUrl = import.meta.env.VITE_WS_URL || 'ws://localhost:8080/ws';
+  const environment = import.meta.env.MODE === 'production' ? 'production' : 'development';
+
+  return {
+    apiUrl,
+    wsUrl,
+    environment,
+  };
+}
+
+export const config = loadConfig();
+
+// Convenience exports
+export const API_BASE_URL = config.apiUrl;
+export const WS_URL = config.wsUrl;
+export const isProduction = config.environment === 'production';