Verified live: indexers->Prowlarr->per-arr QBittorrent download clients with
category routing. Readarr's client parked (qB proxy auth defect in abandoned
upstream). EZTV/1337x parked with reason (CloudFlare-blocked at this egress);
Nyaa/sukebei/RuTor/Byrutor/YTS passed live tests and are enabled. Prowlarr v2
Applications rows now carry real arr baseUrl+apiKeys; before this every sync
attempt threw NullConfig in GetIndexerMappings.