Add a per-project `quality_command` (model + ORM + API + panel + migration 029)
that the pre-submit gate prefers over the lint/typecheck pair. Pointed at the new
`make gate` target (ruff format --check + ruff check + mypy + xenon, no tests),
i_am_done now catches lint, type AND complexity failures in the developer's
workspace before QA — closing the gap where over-complex code only failed in CI.
Falls back to lint+typecheck when unset; a no-op when no commands are configured.
