-- Which model a template role's claw runs on.
--
-- `mint_team_from_template` minted EVERY role of EVERY mission team on one
-- model, because a template had no way to say otherwise: `template_roles` had a
-- slot, a prompt, skills and a brain seed, and no model. So a team whose whole
-- point is an independent reviewer got a reviewer running the same model as the
-- coder it reviews — the correlated failure the cross-provider judge exists to
-- break, reintroduced one layer down.
--
-- NULL means "the mint's default", which is what every existing role gets: this
-- migration changes no behaviour on its own. A template that wants a cheap
-- summarizer or a different-provider reviewer can now say so.
--
-- No CHECK constraint and no FK to a model catalogue, for the same reason
-- `missions.backend` and `missions.validator_model` have none: which models a
-- deployment registered is configuration, not schema. An unknown alias is
-- refused where models are resolved, with a message naming what IS registered.
ALTER TABLE template_roles
    ADD COLUMN IF NOT EXISTS model text;