refactor: remover código morto e exports não utilizados

Remove 6 componentes não utilizados (dashboard-grid, expenses/income
by category widgets, installment analysis panels, fatura-warning-dialog).

Remove funções/tipos não utilizados: successResult, generateApiToken,
validateApiToken, getTodayUTC/Local, formatDateForDb, getDateInfo,
calculatePercentage, roundToDecimals, safeParseInt/Float, isPeriodValid,
getLastPeriods, normalizeWhitespace, formatCurrency wrapper,
InboxItemInput, InboxBatchInput, ProcessInboxInput, DiscardInboxInput,
LancamentosColumnId, 5 funções de anticipation-helpers.

Redireciona imports de formatCurrency para lib/lancamentos/formatting-helpers.

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

lib/utils/string.ts

@@ -23,15 +23,6 @@ export function normalizeFilePath(path: string | null | undefined): string {
 	return path?.split("/").filter(Boolean).pop() ?? "";
 }
 
-/**
- * Normalizes whitespace in string (replaces multiple spaces with single space)
- * @param value - String to normalize
- * @returns String with normalized whitespace
- */
-export function normalizeWhitespace(value: string): string {
-	return value.replace(/\s+/g, " ").trim();
-}
-
 /**
  * Normalizes icon input - trims and returns null if empty
  * @param icon - Icon string to normalize