PO-built prototype (FBM terrain, Whittaker biomes, procedural globe)
with test body definitions for all planet types. Replaces pyplatec
approach. Spike validates the pipeline architecture for batch #817.
Includes handover doc, 9 test body definitions, and updated spike
pipeline documentation. Stale pyplatec outputs removed.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>