Why: env ensure downloads an interpreter and wheels. The real-combination start test allows 120 seconds, and that download made rc1 start time out. Evidence: CI job 5184 timed out in test_U3_real_agent_identity_lifecycle_sqlite on scripts/svc.sh rc1 start. Impact: Start only mounts a base layer that already exists. The first build is an explicit env ensure, run outside start. Refs: Agent-System-Dev pull 570 Co-authored-by: Cursor <cursoragent@cursor.com>