v0.4.3

Deterministic design/build-lane gate hardening (consort-only).

• Migration-reversibility test-list gate. Flags a reversibility/data-preservation test that downgrades by a relative step (alembic downgrade -1) instead of pinning the migration's own revision — fragile the moment a later story moves head. Fail-open (a pinned down_revision / explicit revision escapes).
• Layering gate fail-closed. consort-layering-clean --project-dir . auto-resolves the in-flight feature's architecture.json and runs the import-layering/ORM checks instead of silently exempting a service-backed feature when --architecture is omitted; loud "layering NOT checked" on ambiguity, never a false clean.
• Deterministic layering review backstop. The REVIEW step runs the layering checks regardless of the Navigator's verdict (mirroring ux-adherence), so a rubber-stamp refactor:false can't ship a boundary→model violation — the routable layering-violation smell forces the Driver's refactor.

Full suite 4532 green.