Implements story 2-6: Renderer class with per-aircraft trail history
(deque capped at TRAIL_MAX_DOTS=5), NullDisplay with DEBUG logging,
WaveshareDisplay stub, and end-to-end pipeline smoke test. All 96
tests pass; ruff check and format clean.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Creates the complete src/planemapper/ layout with all module stubs,
provisioning and renderer subpackages, airports.csv data bundle,
systemd unit files, and full test scaffold. All three quality gates
pass: pytest 12/12, ruff check zero violations, ruff format clean.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Matt Edholm