Feat(holidays): Implement database-backed holiday detection system

- Adds a new `MercadosFeriados` table to the database to persist market holidays.
- Implements `HolidayDataFetcher` to update holidays weekly from Finnhub API.
- Implements `IHolidayService` with in-memory caching to check for holidays efficiently.
- Worker service now skips fetcher execution on market holidays.
- Adds a new API endpoint `/api/mercados/es-feriado/{mercado}`.
- Integrates a non-blocking holiday alert into the `BolsaLocalWidget`."

src/Mercados.Api/Program.cs

@@ -5,6 +5,7 @@ using Mercados.Infrastructure.Persistence;
 using Mercados.Infrastructure.Persistence.Repositories;
 using Mercados.Api.Utils;
 using Microsoft.AspNetCore.HttpOverrides;
+using Mercados.Infrastructure.Services;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -32,6 +33,10 @@ builder.Services.AddScoped<ICotizacionGanadoRepository, CotizacionGanadoReposito
 builder.Services.AddScoped<ICotizacionGranoRepository, CotizacionGranoRepository>();
 builder.Services.AddScoped<ICotizacionBolsaRepository, CotizacionBolsaRepository>();
 builder.Services.AddScoped<IFuenteDatoRepository, FuenteDatoRepository>();
+builder.Services.AddScoped<IMercadoFeriadoRepository, MercadoFeriadoRepository>();
+builder.Services.AddMemoryCache();
+builder.Services.AddScoped<IMercadoFeriadoRepository, MercadoFeriadoRepository>();
+builder.Services.AddScoped<IHolidayService, FinnhubHolidayService>();
 
 // Configuración de FluentMigrator (perfecto)
 builder.Services