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

B delivers a substantive dev-workflow improvement (cargo-watch integration, persistent fixture data with reuse/rebasing logic, preferred-port fallback) that meaningfully improves developer iteration speed, though it bundles in an unrelated/likely unintentional HTML removal from forum.rs. A is a clean, minimal, well-justified config simplification (kaocha auto-discovery) that reduces future maintenance friction but is much smaller in scope and impact.