-- Acceso de solo lectura al menu Equipos para usuarios que por su rol no lo ven (compartir el modulo).
-- Lo gestionan admin/superadmin. Idempotente.
CREATE TABLE IF NOT EXISTS device_viewers (
  user_id INT NOT NULL PRIMARY KEY,
  granted_by INT NULL,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  CONSTRAINT fk_device_viewers_user FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
  CONSTRAINT fk_device_viewers_granter FOREIGN KEY (granted_by) REFERENCES users(id) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;