- test_fixture_sweep: extract+validate every fixture PDF on every run;
known extractor/validator gaps are catalogued explicitly and the sweep
fails on any deviation from that catalogue
- tests/fixtures/real/: anonymized XML from real production invoices that
revealed bugs (verified to contain no real-world data); first entry
locks in the FC-tax-number/basis-quantity/spaced-VAT-ID regressions
- CI workflow: uv sync --frozen from lockfile + pytest + docker build
