openai/gpt-chat-latest → A (4:1)

Side A removes the duplicate `server/src/html/forum.rs` monolithic module, adds `forum/mod.rs`, and makes the split `forum/` directory the single module root, eliminating ambiguous module resolution while preserving functionality through extracted submodules like `feed.rs`, `views.rs`, and `thread_morph.rs`. Side B only adds a regression test for rank centrality on a random spanning-tree vote graph; it improves verification but does not change the implementation itself.