Fixes potential integer overflow and invalid input issues:
- Add GRID_MAX constant (8192) to Common.h for global use
- Validate HeightMap dimensions against GRID_MAX to prevent
integer overflow in w*h calculations (65536*65536 = 0)
- Add min > max validation for clamp() and normalize()
- Add unit tests for all new validation cases
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Implement the foundational HeightMap class for procedural generation:
- HeightMap(size, fill=0.0) constructor with libtcod backend
- Immutable size property after construction
- Scalar operations returning self for method chaining:
- fill(value), clear()
- add_constant(value), scale(factor)
- clamp(min=0.0, max=1.0), normalize(min=0.0, max=1.0)
Includes procedural generation spec document and unit tests.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
