openai/gpt-chat-latest → A (4:1)

Side A fixes a concrete correctness bug by removing shared browser sentinel delegates, changing pending sessions to carry an optional agent, ensuring browser actions use no delegate, and adding an integration test proving two different browser users can both vote without hitting the shared `AgentBound` failure. Side B is primarily a broad URL/route refactor and normalization effort (new room route encoding, URL helpers, and canonicalization), which may improve consistency but is largely structural compared with A's targeted functional bug fix backed by regression tests.