feat: add initial project scaffold with Makefile, pyproject.toml, setup.cfg, and CLI entry point

Create the foundational project structure for the zamenyat HTTP content replacement bridge, including a Makefile with targets for environment setup, installation, formatting, and building; a pyproject.toml declaring setuptools as the build backend; a setup.cfg with package metadata, dependencies on the internal app library, and a console_scripts entry point; a README.md with a corrected heading and project description; a __main__.py module implementing argument parsing for host, port, upstream-host, and upstream-port; and an app.py module defining the Application class with async header parsing, connection tracking, and configurable buffer/header size constants.

Makefile

@@ -0,0 +1,29 @@
+BIN = ./.venv/bin/
+PYTHON = ./.venv/bin/python
+PIP = ./.venv/bin/pip
+APP_NAME=zamenyat
+
+all: install build
+
+ensure_repo:
+	-@git init 
+
+ensure_env: ensure_repo
+	-@python3 -m venv .venv 
+
+install: ensure_env
+	$(PIP) install -e . 
+
+format: 
+	$(PIP) install shed 
+	. $(BIN)/activate && shed
+
+build: 
+	$(MAKE) format
+	$(PIP) install build
+	$(PYTHON) -m build 
+
+run:  
+	$(BIN)$(APP_NAME) --host="0.0.0.0" --port=3046 --upstream-host="127.0.0.1" --upstream-port=9999
+
+