~x-ai/grok-latest → B (2:3)

B fixes a concrete production bug: shared WEB_BROWSER_AGENT/INVITE_BROWSER_AGENT sentinels caused AgentBound on the first browser vote and blocked every later human, and it removes those sentinels so UI posts use delegate None with a multi-user regression test. A is a large identity/path split (canonical_path + identity, strict no-@ wire form, optional delegate, reducer stops rewriting) that improves lasting design and enables optional delegates, but much of the diff is mechanical call-site/test churn versus B’s narrower correctness win.