MIGRATION_POLL_INTERVAL_SEC and MIGRATION_POLL_TIMEOUT_SEC were in .env.example and used by phase4, but missing from validate_env() arrays and configure_env.sh prompts. Preflight would not catch invalid values. Now validated as positive_integer and prompted in the REPOSITORIES section of the wizard. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>