Document expanded world scale

Scale ecology and traversal for larger worlds

Expand WorldForge to one-kilometre worlds

WorldForge: prompt-driven region plan, semantic layout map and composite height field

WorldForge: prompt-driven region plan, semantic layout map and composite height field

WorldForge: prompt-driven region plan, semantic layout map and composite height field

WorldForge: prompt-driven region plan, semantic layout map and composite height field

initial commit