v2 already projected todo_list plan artifacts (deriveActivePlanState
existed with zero consumers), but nothing rendered them: todo_list turn
items showed as a bare "Updated tasks" work row, the composer Tasks
drawer never appeared, and the working row had no current-step label.

todo_list items now become inline turn-plan chips (mini step segments,
current step, N/M count, expandable step list) that fold with their
settled turn, ChatView derives the composer Tasks drawer progress and
steps from the running run's plan artifact, and the working row shows
"Working for Xs · <current step>" like main.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>