feat(udt-001): infrastructure (Dapper, BCrypt, JWT RS256, dispatcher)

src/api/SIGCM2.Infrastructure/Persistence/SqlConnectionFactory.cs

@@ -0,0 +1,15 @@
+using Microsoft.Data.SqlClient;
+
+namespace SIGCM2.Infrastructure.Persistence;
+
+public sealed class SqlConnectionFactory
+{
+    private readonly string _connectionString;
+
+    public SqlConnectionFactory(string connectionString)
+    {
+        _connectionString = connectionString;
+    }
+
+    public SqlConnection CreateConnection() => new(_connectionString);
+}

src/api/SIGCM2.Infrastructure/Persistence/UsuarioRepository.cs

@@ -0,0 +1,60 @@
+using Dapper;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Domain.Entities;
+
+namespace SIGCM2.Infrastructure.Persistence;
+
+public sealed class UsuarioRepository : IUsuarioRepository
+{
+    private readonly SqlConnectionFactory _connectionFactory;
+
+    public UsuarioRepository(SqlConnectionFactory connectionFactory)
+    {
+        _connectionFactory = connectionFactory;
+    }
+
+    public async Task<Usuario?> GetByUsernameAsync(string username)
+    {
+        const string sql = """
+            SELECT
+                Id, Username, PasswordHash,
+                Nombre, Apellido, Email,
+                Rol, PermisosJson, Activo
+            FROM dbo.Usuario
+            WHERE Username = @Username
+              AND Activo = 1
+            """;
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync();
+
+        var row = await connection.QuerySingleOrDefaultAsync<UsuarioRow>(sql, new { Username = username });
+
+        if (row is null) return null;
+
+        return new Usuario(
+            id: row.Id,
+            username: row.Username,
+            passwordHash: row.PasswordHash,
+            nombre: row.Nombre,
+            apellido: row.Apellido,
+            email: row.Email,
+            rol: row.Rol,
+            permisosJson: row.PermisosJson,
+            activo: row.Activo
+        );
+    }
+
+    // Flat DTO for Dapper mapping (avoids polluting domain entity with Dapper attributes)
+    private sealed record UsuarioRow(
+        int Id,
+        string Username,
+        string PasswordHash,
+        string Nombre,
+        string Apellido,
+        string? Email,
+        string Rol,
+        string PermisosJson,
+        bool Activo
+    );
+}