refactor: Enhance environment configuration and loading mechanism

- Implement flexible environment variable loading strategy
- Add support for environment-specific and local override configuration files
- Create new `loadEnv.ts` module for dynamic environment configuration
- Update configuration loading in multiple config files
- Remove deprecated `.env.development.template`
- Add setup script for environment validation
- Improve WebSocket error handling and client configuration

src/websocket/client.ts

@@ -74,8 +74,11 @@ export class HassWebSocketClient extends EventEmitter {
         };
 
         this.ws.onerror = (event: WebSocket.ErrorEvent) => {
-          this.emit('error', event);
-          reject(event);
+          const error = event.error || new Error(event.message || 'WebSocket error');
+          this.emit('error', error);
+          if (!this.authenticated) {
+            reject(error);
+          }
         };
 
         this.ws.onmessage = (event: WebSocket.MessageEvent) => {