~anthropic/claude-sonnet-latest → B (75:25)

Side B implements a real, working feature: server-rendered theme switching via cookies (with localStorage migration, /theme route, layout signature changes across many pages) plus a legitimate multi-room URL-prefixing bugfix for ontology/forum links in private rooms, backed by unit tests. Side A is purely a file-split/dedup cleanup removing a duplicate forum.rs (structural refactor with no behavioral change), which is useful hygiene but far less substantive than B's functional additions and bugfixes.