~x-ai/grok-latest → A (3:1)

A completes a lasting API consolidation: delete web_post.rs and the /post|/post/check|/post/redact routes, resolve session once via WebSession/resolve_web_session, and route all forum compose/redact through POST /ui + __rpc__ (forms, client check JS, integration/walkthrough tests). B is a real but narrower ops fix—centralize get-base-url/HOSTNAME, point OAuth callbacks and authUtils at that base/origin, and retarget Fly deploys to staging—valuable durability without restructuring product surface area.