Active Sessions panel lists sessions that are open OR exited-but-within-grace
(barrier state is unconfirmed, so a paid car is presumed possibly-present until
grace expires). Row click → pay/exit modal; 'Open barrier' (paid sessions only —
no payment, no button) fires a human-intervention re-pulse signed as an attributed
anomaly, never a second vehicle_exit. Wiki: booth-exit-flow.md.
Note: the backend (PayStation.activeSessions, ExitFlow.reopenBarrier, routes,
api.ts) landed with the prior commit's shared files.
