Connect CSV export to Profitscaler

One endpoint returns a row per day and the other a row per SKU per day. Add a days parameter for a backfill — 90 days by default, up to 730. Rolling margin per SKU is an aggregation over those rows, done in your tool rather than in ours, deliberately: it belongs where the rest of your reporting logic already lives. Rotating a leaked key is a column update and a new URL in one import, and nothing else is affected.