~anthropic/claude-sonnet-latest → A (6:4)

Side A removes duplicate/dead code paths (ExpandNewThreadForm action, its dispatch handler, and tests) and consolidates the home page to reuse the same SSR compose slot as room pages, simplifying the codebase with a real behavioral unification. Side B is a useful but minor config simplification (auto-discovering test namespaces instead of hand-listing them) that reduces future maintenance friction but has no functional code impact and carries some risk of accidentally picking up unintended test namespaces.