feat(libhttp): integrate WebSocket client into HttpClient

Merge WebSocket client functionality into HttpClient using Boost.Beast,
enabling a single client instance to handle both HTTP (libcurl) and
WebSocket (ws:// and wss://) protocols. Backward-compatible type aliases
(WebSocketClient, WebSocketClientBase) preserve existing code.

Changes:
- Add synchronous WebSocket client: ws_connect/ws_send/ws_recv/ws_close
- Support ws:// (plain TCP) and wss:// (TLS with SNI) connections
- Layered stream architecture with beast::tcp_stream for timeout support
- Binary message support via ws_send_binary()
- Update Makefile to link libcurl (-lcurl)
- Add README.md documenting unified HttpServer + HttpClient API

libhttp/Makefile

@@ -7,7 +7,7 @@ INCLU_SDIR := inc
 CPP := g++
 INCS := -I inc -I/opt/homebrew/include
 CPPFLAGS := --std=c++20 -O3 -pipe -Wall -Werror
-LIBS := -L/opt/homebrew/lib -lssl -lcrypto -lpthread
+LIBS := -L/opt/homebrew/lib -lssl -lcrypto -lcurl -lpthread
 BUILD_TDIR := build
 $(shell mkdir -p $(BUILD_TDIR))