Drafted via superpowers:feature-spec. Plan 6 of 7 in the skill
migration. Surface frozen at 4 cost-routable skills (code_review,
debug, retrospective, trainer); LiteLLM proxies model choice; pass-
rate drives the route decision with default-to-local plus an env
kill switch for the empty-data window. Plan 7 amendment baked in:
internal/skills/{review,debug,retrospective,trainer} survive Plan 6.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
