204302bd64
Port from Kilo-Org/kilocode#12698: report signal-terminated commands with a human-readable note instead of a bare numeric exit code. Kilo's fix settles a signal-killed process as the conventional 128+signum exit code so its bash tool stops hanging. Hermes already produces numeric codes for signal deaths (subprocess -signum, or the shell's 128+signum), but the model saw a bare exit_code=-9 or 137 and burned turns mis-diagnosing (137 = OOM kill being the most common). This adapts the idea to Hermes' existing exit-code semantics tier: - _interpret_signal_exit(): maps negative codes (definite signal death) and the 128+signum band (hedged with 'usually') to a note naming the signal and its likely cause, wired into _interpret_exit_code() ahead of the per-command semantics table. - Curated signal table (SIGKILL/SIGSEGV/SIGTERM/SIGABRT/...) so ambiguous application exit codes are never mislabeled; uncurated 128+N codes stay silent, SIGINT is excluded (executor's interrupt-marker path owns rc=130). - Notes surface via the existing exit_code_meaning result field. E2E verified against real SIGSEGV/SIGKILL processes.