Add SABnzbd+Transmission to radarr-4k/sonarr-4k with distinct categories (sabnzbd
movies-4k/tv-4k, transmission radarr-uhd/sonarr-uhd; Transmission forbids digits) so
they dont cross-import the 1080p instances. Packaged into deploy-arrs-4k.yml via an
idempotent ensure-arrs-4k-dl.py (changed=0). Homepage Radarr 4K/Sonarr 4K tiles
(HOMEPAGE_VAR keys, siteMonitor). 4K path proven: Obsession routed to radarr-4k,
grabbed WEBDL-2160p, 1080p rejected 'not wanted in profile'. Keys via vault, no secrets.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>