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

Side B removes substantial duplicated OAuth/HTTP/test-harness code across four test files by consolidating into shared test.common and test.oauth modules, reducing maintenance burden and duplication risk with no behavior change. Side A is a reasonable UI refinement (grouped CLI panel, JS-safety assert) but is smaller in scope and purely cosmetic/feature-polish rather than structural improvement.