Fix scanline gap bug and optimize rasterize performance

The scanline fill had a row-clamping bug (floor(r1)-1 instead of
ceil(r1)-1) that left every other row empty in curved polygons.

Also adds three performance improvements:
- Vectorized edge extraction via shapely 2.0 array ops (~13x faster)
- Sorted edge table with binary search in scanline kernel (~7-50x faster)
- Single-pass geometry classification to avoid redundant iteration

Author: brendancol