Add /explore-minimax and explore-minimax-run memory files, backfill
skill-ask-minimax / skill-ask-minimax-with-context entries, index them in
MEMORY.md. ask-minimax-usage.md gains the exploration use case and an
explicit no-secrets rule.
Claude-Session: https://claude.ai/code/session_01Ku87DDWwbJkTx6SuV3sQDc