- New app shell: persistent sidebar with navigation, quick-add action, and dark-mode toggle - Light/dark design tokens and theme toggle infrastructure - Redesigned Planilha screen: month-scoped balance card, spending-distribution donut, click-to-edit table, budget-alert dashboard - Redesigned all Planilha modals (Categorias, Orçamento, Recorrentes, Meus parcelamentos, Fechar mês, Novo lançamento, Exportar, and a new Importar modal) - Split subs.cljs/events.cljs into feature-scoped fintrack.model.* namespaces (MVVM Model layer) - Added cljfmt tooling and reformatted the codebase - Polish pass: hover/focus states, dead-code cleanup, theme-token consistency