scenario_attempts.status = 'abandoned' (a valid value since Phase 3B,
never previously set by anything) now gets set on: environment
destroy/reset, logout, session expiry (piggybacked on the existing hourly
session sweeper - no new background job), and switching to a different
scenario while one is still open. Never an academic failure marker -
result stays NULL, history is preserved. Call-site wiring in
server.js/admin-routes.js lands in the next commit alongside other
platform hardening in those same files.
