The Claude Code plugin ships a SessionEnd hook that logs a cheap timestamp
+ PWD marker to ~/.skillopt-sleep/session-end.log so the next nightly cycle
knows there is fresh activity to harvest. The Devin plugin had no
equivalent — nightly runs relied on cron alone with no activity signal.
Devin CLI supports SessionEnd hooks via .devin/hooks.v1.json (same JSON
format as Claude Code), firing with {"reason": "..."} on stdin and setting
DEVIN_PROJECT_DIR to the project root.
Add hooks/hooks.v1.json (SessionEnd hook config) and
hooks/on-session-end.sh (mirrors the Claude Code on-session-end.sh: append
timestamp + project dir, non-blocking, no API spend). Update README install
instructions with the optional copy step.
