~x-ai/grok-latest → B (2:1)

B fixes systemic broken redirect/OAuth base URLs by centralizing HOSTNAME-aware get-base-url (replacing divergent hardcoded sorter.social/InetAddress cases across linear/login/oauth/spotify/twitter/youtube) and making the client use window.location.origin, plus aligning deploy to staging—core correctness for multi-host. A adds useful garden UX (edge vote counts, HUD unpin via set_garden_pin clear) with tests, but it is incremental product polish rather than a cross-cutting host bugfix.