fix: Proxy configuration improvements

src/whatsapp/dto/proxy.dto.ts

@@ -1,4 +1,12 @@
+class Proxy {
+  host: string;
+  port: string;
+  protocol: string;
+  username?: string;
+  password?: string;
+}
+
 export class ProxyDto {
   enabled: boolean;
-  proxy: string;
+  proxy: Proxy;
 }