Refactor terminal state store to use granular thread selectors

- Replace `getTerminalState` reads with `selectThreadTerminalState` in ChatView and Sidebar
- Split terminal reducer into pure thread terminal operations used by the Zustand store
- Drop persisted default thread entries and add tests for the new operation helpers
246624ad3cJulius Marminge committed on 3/2/2026, 9:13:19 PM· committed by Julius Marmingeparent410444a
5 files changedLine totals unavailable