style(ui): polimento visual — tema, cards, dark mode e landing page

Raio de borda global 0.625rem → 0.7rem; ajustes finos em --card e --border.
DotPattern removido do layout, tela de auth e landing page.
Account-card redesenhado (cores de saldo, tooltip de flags de exclusão).
Budget-card, card-item, calendário (day-cell, event-modal) com layout revisado.
Auth-card-shell simplificado (sem glassmorphism/blob). Landing page com
mainFeatures + extraFeatures em grid único e dark mode nos botões de CTA.
Imagens de preview da landing atualizadas. CSS --data-7..10 removidas.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/features/transactions/components/dialogs/anticipate-installments-dialog/anticipate-installments-dialog.tsx

@@ -341,7 +341,7 @@ export function AnticipateInstallmentsDialog({
 
 					{/* Seção 3: Resumo */}
 					{selectedIds.length > 0 && (
-						<div className="rounded-lg border bg-muted/20 p-3">
+						<div className="rounded-lg border p-3">
 							<h4 className="text-sm font-semibold mb-2">Resumo</h4>
 							<dl className="space-y-1.5 text-sm">
 								<div className="flex items-center justify-between">

src/features/transactions/components/dialogs/transaction-details-dialog.tsx

@@ -82,7 +82,7 @@ export function TransactionDetailsDialog({
 
 				<div className="min-w-0 max-h-[60vh] overflow-x-hidden overflow-y-auto text-sm">
 					<div className="min-w-0 space-y-4">
-						<section className="rounded-lg border bg-muted/20 p-3">
+						<section className="rounded-lg border p-3">
 							<div className="flex items-start justify-between gap-3">
 								<div className="min-w-0">
 									<p className="text-xs uppercase tracking-wide text-muted-foreground">