fix(minimax): align SKILL.md source description with refreshed catalog (#416)

PR #415 refreshed the model catalog and updated the generated mirror
skills/cli-anything-minimax/SKILL.md, but left the canonical source
description describing only MiniMax-M3 / speech-2.8-hd. The root-skills
validator flags the mirror as containing content absent from its source,
failing "Check Root Skills" on main. Update the source description to match
so the mirror is a faithful sync (sync_root_skills.py now reports no drift).