perf(gamelogic): Bound terrain deformation scans

[bobtista]

• Fixes Terrain deformation loops scan from row 0 wastefully #3257
• Merge after unify(map): Merge and move GameLogic map headers and implementations to Core #3189

createCraterInTerrain and flattenTerrain calculate iMin.y, but their inner loops start at row 0. The shape checks reject rows outside the affected area, so this wastes more work as the Y position increases.

Now starts the loops at MAX(0, iMin.y), skipping rows below the affected area while preserving the existing map-edge behavior.

Todo:

• Testing