Replace mechanical text extraction in session-end.js and pre-compact.js
with LLM-generated summaries using `claude -p`. Summaries now capture
design decisions, resolved bugs, changed files, and carry-over context
rather than just truncated user message snippets.
- Add scripts/lib/llm-summary.js: generateSessionSummary, extractConversationText,
getContextRemainingPct, getContextThreshold, getLLMModel
- Update scripts/hooks/session-end.js: trigger LLM when context < 20% or
every 50 messages (env-configurable via ECC_LLM_SUMMARY_*)
- Update scripts/hooks/pre-compact.js: generate LLM summary right before
compaction and write it to the active session .tmp file
- Add tests/lib/llm-summary.test.js: 18 unit tests
- Update tests/hooks/hooks.test.js: 3 integration tests for new behaviour
Recursion guard: sets ECC_SKIP_LLM_SUMMARY=1 in subprocess env so Stop
hooks fired by the claude -p subprocess do not re-enter summarisation.
Requires no ANTHROPIC_API_KEY — reuses Claude Code's own authentication.
Co-authored-by: Hiroshi Tanaka <hiroshi_tanaka@MBAM3.local>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
