Crystallize — distil session patterns into reusable skills

Invoke when the CTO says /crystallize, "crystallize", "extract knowledge", or "what have we learned?". Also auto-suggested when session count is a multiple of 10 (the session-end hook checks .great_cto/.last-crystallize).

The knowledge-extractor agent (Opus) does the heavy lifting. This skill orchestrates the workflow and emits the final report.

Session-end hint integration: The session-end hook checks .great_cto/.last-crystallize and suggests running /crystallize when the session count exceeds last_sessions + 10. Run this skill after ≥10 sessions to keep extracted skills current.

Step 1 — Gather raw material