eos_init Subroutine

   subroutine eos_init(this, grid)
      class(eos_t), intent(inout) :: this
      type(hgrid_t), intent(in) :: grid
      if (.false.) this%rho0 = real(grid%nx_total, wp)
      ! NOTE: the device-callable-variant gate is NOT run here anymore.
      ! `eos%variant` is still at its default at `init` time; the config
      ! knob (`&ocean_eos_nml eos=...`) is applied later, in
      ! `configure_ocean_pgf`, which calls `eos_validate` POST-config
      ! (so it sees the real variant) plus the FV_WRIGHT+Roquet fail-loud.
      this%is_init = .true.
   end subroutine eos_init