- Introduced a new example `dual_noise_demo.cpp` to showcase the base and surface generation system.
- Updated biome properties to include ice thresholds and surface feature parameters.
- Enhanced chunk structure to support biomes for sub-chunks.
- Refactored terrain generation logic to separate base terrain and surface feature generation.
- Improved biome determination logic to include new biomes and their properties.
- Updated tile representation to use enums for base and surface tile types.
- Added detailed analysis of generated terrain and sample tile outputs in the demo.
Signed-off-by: szdytom <szdytom@qq.com>
