Widens @Krionex's PR #16933 fix to cover the second bug class at the sibling
site. natural mode used to pass env values through int() before the PR
caught mis-typed values crashing the gateway; custom mode had the exact
same bug one branch away (HERMES_HUMAN_DELAY_MIN_MS=oops in custom mode
still crashed). Same try/except/fallback pattern, scoped to the two
int() calls that feed random.uniform().