bufferscape: Distance-Weighted Landscape Composition in Buffers Around Point Locations

Characterises the environment surrounding point locations by computing land-cover composition within circular buffers directly from vector polygons, without rasterisation. For each site and each class it returns the exact surface area inside the buffer and a distance-decay weighted effective area in which the kernel is integrated over polygon geometry rather than evaluated at the polygon centroid, avoiding the large bias the centroid approximation introduces for elongated features passing close to the site.