The #666 pytest gate ran `uv sync --frozen`, but tradein-mvp/backend/uv.lock
is gitignored → absent in a fresh CI checkout → 'Unable to find lockfile…
--frozen was provided' → test job failed → build+deploy skipped (deploy still
blocked after the PEP668 uv-install fix). Resolve from pyproject.toml instead
(uv sync, dev group included), matching the Dockerfile's `uv sync --no-dev`.