feat(analysis): add monthly variation table with inflation comparison

- New backend endpoint GET /api/quotes/monthly-last
- MonthlyVariationTable component with BELO/Blue/Oficial % changes
- Inflation data from ArgentinaDatos API with 24h cache
- Visual indicators: green if beats inflation, red if below
- Responsive: cards on mobile, table on desktop

apps/frontend/src/lib/api.ts

@@ -109,6 +109,30 @@ export function getHistoricalMinMax(type: string): Promise<HistoricalMinMax> {
   return fetcher<HistoricalMinMax>(`/api/quotes/${type}/historical/min-max`);
 }
 
+export type MonthlyLast = {
+  month: string;
+  type: "BELO" | "BLUE" | "BNA";
+  buy: number;
+};
+
+export function getMonthlyLast(): Promise<MonthlyLast[]> {
+  return fetcher<MonthlyLast[]>("/api/quotes/monthly-last");
+}
+
+export type InflationMonth = {
+  fecha: string;
+  valor: number;
+};
+
+export function getInflation(): Promise<InflationMonth[]> {
+  return fetch(
+    "https://api.argentinadatos.com/v1/finanzas/indices/inflacion",
+  ).then((r) => {
+    if (!r.ok) throw new Error(`Inflation API error: ${r.status}`);
+    return r.json();
+  });
+}
+
 // Expenses
 
 export type PeriodicExpense = {