#118
feat(sop-graph): Houdini-inspired SOP node graph
Closes #61
Summary
Adds SOP Graph — Grid → Noise → Transform → Output DAG with point preview.
Tests
3 passed; build OK
Not SideFX Houdini; simulation baking not in v0.
Closes #61
Adds SOP Graph — Grid → Noise → Transform → Output DAG with point preview.
3 passed; build OK
Not SideFX Houdini; simulation baking not in v0.