~x-ai/grok-latest → B (1:3)

B enforces real vote-ratio invariants (both sides ≥ 1, ≤ 100) across DSL parse, UI POST, and reducer, with unit/integration/browser test coverage—fixing invalid graph edges. A mainly adds a staging plan.md plus a thin RouteContext newtype around ThreadNav without migrating call sites or landing ItemId, so its lasting code impact is scaffolding only.