test(architecture): eliminate subprocess pytest/mypy from tests

post-rewrite wiring audit: Phases 1-5 (sécurité, méthodologie, moteurs, zombie, naming)

feat(sprint-H.4)!: drop _legacy/ prefix — interfaces/{cli,web} consolidées

feat(sprint-H.2.c-d)!: suppression complète de adapters/legacy_engines/ et adapters/legacy_pipelines/

feat(sprint-F)!: web/ → interfaces/web/_legacy/ (Phase 9)

feat(sprint-G)!: cli/ → interfaces/cli/_legacy/ (Phase 10)

feat(migration): Lot E — engines/ + modules/ → adapters/legacy_*/ (suppression)

feat(sprint-A5): concurrence + perf + lazy reports + corpus de référence

feat(docs): Sprint A2 — Tests de cohérence documentation (m-12 + gates A13/A14)