stop-liquidate-restart

Stop trading safely on a running vike-tradehub node from an agent — halt new risk (set_trading_state halted / reducing / active), cancel every resting order (mass_cancel), close positions (flatten, market_exit), and restart cleanly. Use when asked to halt, pause, stop, kill-switch, emergency-exit, panic, go flat, liquidate, close everything, cancel all orders, resume trading, or restart a node — and to know what a…