Consider removing `Socket.connect` from client connect method

[huynguyennovem]

Consider removing shelf_web_socket pkg and its usage in client for connecting to server approach.

Background:
A Shelf server (started with shelf_io.serve) is an HTTP server. It expects clients to send proper HTTP requests (with method, headers, path, etc.) and it responds with proper HTTP responses (status code, headers, body).
Socket.connect from dart:io creates a raw TCP socket. It gives you a low-level byte stream with no HTTP protocol handling.

If using Socket.connect to. connect to a Shelf server:

1. We can establish the TCP connection.
2. But when we send raw bytes, the Shelf handler will usually not understand them as a valid HTTP request → it will likely return 400 Bad Request or close the connection.

Method	Recommended?	Use Case	Code Style
http package (http.get, http.post, etc.)	Best	Normal REST API, JSON, file upload, etc.	High-level
HttpClient (dart:io)	Good	When you don't want extra dependencies	Medium
Socket.connect	Avoid	Only if you want raw TCP (not HTTP)	Low-level
WebSocket	Good	Real-time bidirectional (use shelf_web_socket on server)	High-level

Proposal

→ Use http pkg with its methods for the best fit to server serving currently.