session-end.js: Extract meaningful summaries from CLAUDE_TRANSCRIPT_PATH
instead of writing blank template files. Pulls user messages, tools used,
and files modified from the session transcript JSONL.
session-start.js: Output the latest session summary to stdout (via the
output() helper) so it gets injected into Claude's conversation context,
instead of only logging to stderr which just shows briefly in the terminal.
87d19f97a6