Count the positions and traders that ever opened each basket

Reports, per requested basket key, how many positions — and how many distinct traders — have ever opened that basket: cumulative best-effort counters bumped at open, never decremented on close. A basket is named by its canonical key — the basketKey /markets/baskets reports, derivable client-side with deriveBasketKey from @pear-protocol/utils. Counts are summed over the connectors in scope that stored the key, and an absent connector puts every venue in scope, so a trader active on two venues counts on each. Positions opened entirely on the exchange are excluded, so a count only reports Pear activity.

curl -X POST "https://example.com/markets/baskets/positions" \  -H "Content-Type: application/json" \  -d '{    "basketKeys": [      "9f2c1b7a4e6d3f8091a5c7e2b4d6f8a0c3e5079b1d3f5a7c9e1b3d5f7a9c1e3d5"    ]  }'

{  "counts": [    {      "basketKey": "string",      "opened": 0,      "traders": 0    }  ]}