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

Side A is a clean, self-contained refactor that removes ~200 lines of duplicated HTTP/OAuth/test-harness boilerplate across four test files into shared `test.common`/`test.oauth` helpers, improving maintainability without touching production code. Side B improves the dev fixture script (cargo-watch, persistent data dir) but bundles in an unrelated and unexplained removal of room heading/breadcrumb markup in `server/src/html/forum.rs`, which looks like an accidental regression to production HTML mixed into a 'dev script' commit.