Constant EXIT_TIMED_OUT 

pub const EXIT_TIMED_OUT: u8 = 4;

A tune/simulate run was aborted because [tuning].timeout_secs elapsed before the engine reported completion; the loop was restored to its pre-test mode, exactly like EXIT_ABORTED. Distinct from it so a scheduler’s alerting can tell “this run had to be killed for running too long” (possibly a stuck relay, a misconfigured tag mapping, or a stalled driver read – worth investigating) apart from “an operator stopped it on purpose” (routine). See commands::tune::TuneOutcome::TimedOut and AGENTS.md’s cli-safety section.