openai/gpt-chat-latest → A (5:1)

Side A introduces a new `RouteContext` abstraction with a dedicated routing module, re-exports it, and documents a concrete migration plan toward separating item identity (`ItemId`) from routing and presentation. Although much of the commit is planning documentation, it also adds reusable routing infrastructure that can support future refactoring, whereas Side B mainly removes parameters and stops updating the `#vote-compare-preview` region, simplifying an existing function without introducing comparable architectural value.