V152: MAX HEIGHT actual ocean height, arrival contours kept on 1m shoreline-equivalent basis

Base: v151_max_height_actual_ocean

Changes:
- Keep MAX HEIGHT / max-wave color scale as actual grid-cell ocean wave height.
- Restore MAX+arrival contour timing threshold to 1m shoreline-equivalent height.
- OCEAN_MAX_HEIGHT_ARRIVAL_SHORELINE_EQUIV_ENABLED is now 1.
- Station/JESIM 1m shoreline-equivalent gauge values remain unchanged.

Rationale:
The MAX HEIGHT layer is used to inspect offshore propagation and should not be converted to 1m-depth coastal-equivalent height.
However, arrival-time bands are intended as coastal warning-style timing, so their 5 cm threshold should remain on the 1m shoreline-equivalent basis.
