openai/gpt-chat-latest → A (4:1)

Side A makes a substantive storage design change: it replaces the durable `Deque` with an append-only `List`, removes post-commit trimming, applies the recent-vote cap at query time, bumps the schema version, and adds a test verifying the new loading behavior. Side B is primarily a codebase reorganization that deletes the duplicate `forum.rs` and splits functionality into `forum/` modules, improving maintainability but largely preserving existing behavior.