Addresses issue #278 - sprint-diagram command not discoverable after Sprint 4.
Root cause: Claude Code discovers skills at session start. Commands added
during a session are NOT discoverable until restart.
Prevention: Added step 7 "New Command Verification" to sprint-close workflow:
- Reminds about session restart requirement
- Creates follow-up verification task
- Explains why this happens
Lesson learned created: lessons/patterns/sprint-4---new-commands-not-discoverable-until-session-restart
Closes#278
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>