Step 6 of v2.0 plan. SessionStart hook fires on source: resume or
source: compact, walks up to 3 levels searching for
NEXT-SESSION-*.local.md, injects content via additionalContext, and
archives the file (rename to *.archived.local.md) to prevent stale-load
in later sessions. 9 tests cover sources, multi-level search,
topic-slug variants, archive filtering, malformed payload.
Step 4 of v2.0 plan. statusLine hook reads context_window.used_percentage
from stdin payload and prints display-only hint at 60% / 70%. NEVER runs
git (research/03 — statusLine scripts can be cancelled mid-flight, unsafe
for side effects). 9 tests cover thresholds, null payload, malformed JSON.
Includes hook-helper.mjs copied from llm-security as test infrastructure.