npm test now preloads tests/helpers/no-session-id.mjs, which deletes CLAUDE_CODE_SESSION_ID before any test file loads, and the 18 files that spread process.env into a child use childEnv() instead (23 sites). A live session's stop guard is no longer pointed at a temp-repo lock (S133).
engines stays >=18: --import exists from Node 18.18/20.6, and the quoted test glob already needs Node 21 (criteria-runner NODE_GLOB_MAJOR), so the real floor does not move.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
