- Add devSessionCookieMiddleware() to devBypass.ts (production hard-guard FIRST) - Issues local-session JWT cookie for DEV_USER when no cookie present under bypass - Pure no-op when NODE_ENV=production, DEV_AUTH_BYPASS!=true, or secret not set - Mount devSessionCookieMiddleware() after devAuthBypass() in index.ts - Existing devBypass tests: 3/3 pass; typecheck: exit 0