Based on this discussion, we can refine the plan shape index bounds counters to be more accurate, with a definition that's more useful for our analysis:

https://mongodb.slack.com/archives/C0C3QGTEV38/p1790865637365769?thread_ts=1790794577.275279&cid=C0C3QGTEV38

Here is the current definition: https://github.com/10gen/mongo/blob/aeb839c4b21a0d5b845cebf31258582946ee5d57/src/mongo/db/query/query_stats/plan_shape_counters/plan_access_path_counters.cpp#L78