openai/gpt-chat-latest → B (6:5)

Both commits implement the core fix by changing pending sessions and poll responses to use `Option<String>` for delegates, removing browser sentinel delegates, updating UI posts to pass `None`, and adding an integration test proving two browser users can vote without `AgentBound` conflicts. Side B goes further by removing the obsolete browser-sentinel attribution logic (`is_browser_sentinel_delegate`, related re-exports, and HTML rendering/tests), simplifying authorship handling so the codebase consistently treats browser users as having no delegate rather than preserving legacy sentinel behavior.