feat: initial SOCKS5 proxy with chain support

Asyncio-based SOCKS5 server that tunnels connections through
configurable chains of SOCKS5, SOCKS4/4a, and HTTP CONNECT proxies.
Tor integration via standard SOCKS5 hop.

Makefile

@@ -0,0 +1,14 @@
+.PHONY: install test lint clean
+
+install:
+	pip install -e .
+
+test:
+	pytest tests/ -v
+
+lint:
+	ruff check src/ tests/
+
+clean:
+	rm -rf build/ dist/ src/*.egg-info
+	find . -type d -name __pycache__ -exec rm -rf {} +