skill-retro — grade the agent setup from real sessions

Privacy is the contract. Everything runs locally. Transcripts are condensed, secret-redacted, chmod-0600, and never uploaded — the only shareable artifact is the report the user chooses to share.

Run from the repo being graded. Every artifact goes to one fresh scratch dir, never into the repo:

RUN="$(mktemp -d "${TMPDIR:-/tmp}/skill-retro-XXXXXXXX")"
python scripts/collect_sessions.py --out "$RUN"          # 1 — harvest + redact