Write the Fresh-Folder Runbook

Finish README.md for someone starting in a new empty extracted folder. State Python 3.10+ and make every command select the environment interpreter directly; activation and shell state are unnecessary.

Under macOS and Linux, include this exact order:

python3 -m venv .venv
./.venv/bin/python -m pip install -r requirements-dev.txt
./.venv/bin/python -m pytest -q
./.venv/bin/python api_catalog.py --help

Under PowerShell, include:

py -3 -m venv .venv
.\.venv\Scripts\python.exe -m pip install -r requirements-dev.txt
.\.venv\Scripts\python.exe -m pytest -q
.\.venv\Scripts\python.exe .\api_catalog.py --help

Explain that a runtime-only user installs requirements.txt instead, pip uses the interpreter’s configured package index, and an import failure is repaired by returning to the extracted project root. Never recommend global pip, activation, or execution-policy changes.

The downloaded project can rebuild, import, test, and show help off-site. Its fixed practice-api hostname is internal to Python Land, so an actual fetch is not expected to succeed after download. Do not add a public/configurable host, secret, or environment-variable escape hatch.