feat: Define data models and set up DB connection with Dapper

src/Mercados.Infrastructure/Persistence/IDbConnectionFactory.cs

@@ -0,0 +1,9 @@
+using System.Data;
+
+namespace Mercados.Infrastructure.Persistence
+{
+  public interface IDbConnectionFactory
+  {
+    IDbConnection CreateConnection();
+  }
+}

src/Mercados.Infrastructure/Persistence/SqlConnectionFactory.cs

@@ -0,0 +1,24 @@
+using Mercados.Infrastructure.Persistence;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Configuration;
+using System.Data;
+
+namespace Mercados.Infrastructure
+{
+  public class SqlConnectionFactory : IDbConnectionFactory
+  {
+    private readonly string _connectionString;
+
+    public SqlConnectionFactory(IConfiguration configuration)
+    {
+      _connectionString = configuration.GetConnectionString("DefaultConnection")
+          ?? throw new ArgumentNullException(nameof(configuration), "La cadena de conexión 'DefaultConnection' no fue encontrada.");
+    }
+
+    public IDbConnection CreateConnection()
+    {
+      // Dapper se encargará de abrir y cerrar la conexión automáticamente.
+      return new SqlConnection(_connectionString);
+    }
+  }
+}