Autonomous metric-optimization loop - run N bounded iterations against a mechanical metric, commit each attempt, auto keep/discard on the number, revert regressions. Use to improve a measurable metric: test coverage, bundle size, lint/type-error count, p95 latency, LOC. Triggers: 'drive coverage up', 'reduce bundle size', 'get lint errors to zero', 'optimize <metric> over iterations', 'keep/discard loop'.
