Once the isolated idLookup workload (SERVER-133481) has been developed and proven stable in regular runs (noise levels acceptable, cron matrix settled), add it to docs/workloads/high_value_workloads.md so it counts toward release criteria.

This follows from the HELP-97449 postmortem (see also CLOUDP-439350): search workloads that only run in mongot-perf don't provide server release coverage without DSI HVW integration, and the idLookup path was the actual source of the regression that triggered that incident.