v0.3.0

What's New

• Grid operations — new clip, resample, reproject, merge, and fill_gaps functions for preparing and transforming bathymetric grids
• Volume & area — volume and area calculations between depth levels; hypsometric_curve gains absolute=True for depth-area curves in real units
• New data sources — load_etopo (NOAA ETOPO 2022 global relief) and load_noaa_crm (NOAA Coastal Relief Model, ~90 m, US coastal waters)
• Grid operations example — new notebook (examples/grid_operations.ipynb) demonstrating the grid module

Fixed

• fill_gaps now raises a ValueError when all input values are NaN, rather than returning silently
• Internal assertion in profile point spacing calculation replaced with an explicit ValueError

Infrastructure

• ipywidgets added to notebook optional dependencies (uv sync --extra notebook)

Changelog

Full details: CHANGELOG.md