perf: otimizar dashboard com indexes, cache e consolidação de queries (v1.3.0)

- Adicionar indexes compostos em lancamentos para queries frequentes
- Eliminar ~20 JOINs com pagadores via helper cacheado getAdminPagadorId()
- Consolidar queries: income-expense-balance (12→1), payment-status (2→1), categories (4→2)
- Adicionar cache cross-request via unstable_cache com tag-based invalidation
- Limitar scan de métricas a 24 meses
- Deduplicar auth session por request via React.cache()

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

app/(dashboard)/lancamentos/actions.ts

@@ -395,7 +395,10 @@ const buildShares = ({
 		) {
 			return [
 				{ pagadorId, amountCents: primarySplitAmountCents },
-				{ pagadorId: secondaryPagadorId, amountCents: secondarySplitAmountCents },
+				{
+					pagadorId: secondaryPagadorId,
+					amountCents: secondarySplitAmountCents,
+				},
 			];
 		}