refactor(core): move app para src e padroniza estrutura

src/shared/components/month-picker/month-navigation.tsx

@@ -0,0 +1,80 @@
+"use client";
+
+import { useRouter } from "next/navigation";
+import { useEffect, useTransition } from "react";
+import { Card } from "@/shared/components/ui/card";
+import { getNextPeriod, getPreviousPeriod } from "@/shared/utils/period";
+import LoadingSpinner from "./loading-spinner";
+import NavigationButton from "./nav-button";
+import ReturnButton from "./return-button";
+import { useMonthPeriod } from "./use-month-period";
+
+export default function MonthNavigation() {
+	const { period, currentMonth, currentYear, defaultPeriod, buildHref } =
+		useMonthPeriod();
+
+	const router = useRouter();
+	const [isPending, startTransition] = useTransition();
+
+	const currentMonthLabel = `${currentMonth.charAt(0).toUpperCase()}${currentMonth.slice(1)} ${currentYear}`;
+	const prevTarget = buildHref(getPreviousPeriod(period));
+	const nextTarget = buildHref(getNextPeriod(period));
+	const returnTarget = buildHref(defaultPeriod);
+	const isDifferentFromCurrent = period !== defaultPeriod;
+
+	// Prefetch otimizado: apenas meses adjacentes (M-1, M+1) e mês atual
+	// Isso melhora a performance da navegação sem sobrecarregar o cliente
+	useEffect(() => {
+		// Prefetch do mês anterior e próximo para navegação instantânea
+		router.prefetch(prevTarget);
+		router.prefetch(nextTarget);
+
+		// Prefetch do mês atual se não estivermos nele
+		if (isDifferentFromCurrent) {
+			router.prefetch(returnTarget);
+		}
+	}, [router, prevTarget, nextTarget, returnTarget, isDifferentFromCurrent]);
+
+	const handleNavigate = (href: string) => {
+		startTransition(() => {
+			router.replace(href, { scroll: false });
+		});
+	};
+
+	return (
+		<Card className="flex w-full flex-row p-4 sticky top-16 z-10 backdrop-blur-sm bg-card/30">
+			<div className="flex items-center gap-1">
+				<NavigationButton
+					direction="left"
+					disabled={isPending}
+					onClick={() => handleNavigate(prevTarget)}
+				/>
+
+				<div className="flex items-center">
+					<div
+						className="mx-1 space-x-1 capitalize font-semibold"
+						aria-current={!isDifferentFromCurrent ? "date" : undefined}
+						aria-label={`Período selecionado: ${currentMonthLabel}`}
+					>
+						<span>{currentMonthLabel}</span>
+					</div>
+
+					{isPending && <LoadingSpinner />}
+				</div>
+
+				<NavigationButton
+					direction="right"
+					disabled={isPending}
+					onClick={() => handleNavigate(nextTarget)}
+				/>
+			</div>
+
+			{isDifferentFromCurrent && (
+				<ReturnButton
+					disabled={isPending}
+					onClick={() => handleNavigate(returnTarget)}
+				/>
+			)}
+		</Card>
+	);
+}