Replaces placeholder stubs in test_models.py, test_gpio_ctrl.py, and
provisioning/test_provision_loop.py with real assertions. Adds new
test_scaffold.py covering AC3 file-presence, importlib.resources
airports.csv load, constants completeness, and main.py provisioning
import guard. Extends ruff per-file-ignores so tests/provisioning/*.py
may import from planemapper.provisioning. All 22 tests pass; ruff
check and format --check both clean.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Matt Edholm