Function fdtd_wave_step_dsl 

pub fn fdtd_wave_step_dsl(
    pressure: &[f32],
    pressure_prev: &mut [f32],
    c2: f32,
    damping: f32,
    pos: GridPos,
)

FDTD wave equation kernel using the GridPos DSL.

This version uses the same API as the CUDA-transpiled version, demonstrating that the Rust DSL code works identically on CPU.

The function signature matches what #[stencil_kernel] would generate:

fn fdtd_wave_step(
    pressure: &[f32],
    pressure_prev: &mut [f32],
    c2: f32,
    damping: f32,
    pos: GridPos,
)