old combat sessions always hang around in the zone query.

after 5 hours of (wrongly) investigating issues with combat I had enough combat session to start noticing the affects of all the old sessions in the data (large query size, long loops)

we should probably change the edges so that finalizing actually disconnects the item from the zone query, either by mounting it on tiles or something else.

this would be a contract change, so not ideal.

I believe we needed them to stick around because of session bags ... however we now how the player wallet, so could send rewards directly there and drop the need for reward bags entirely (which would also be a perf/query win)