EnGen OS v0.1.150
Clean-VM-proven fresh install. Fixes the last 3 fresh-install blockers (curl installer shasum->sha256sum fallback, checksum double-append, Herdr made optional) + the brew formula wrapper path. Verified end-to-end on a stock Debian 12 VM: curl|bash -> working console + Cortex 6/6 healthy + first-email admin login.