- Add gradient functions: linear, radial, and multi-stop color maps
- Add RGBA strip rotation with bilinear interpolation
- Add shadow compositing with optional Gaussian blur
- Add combined place_text_strip_fx_jax pipeline (gradient + rotation + shadow)
- Add 7 new S-expression bindings for all FX primitives
- Extract shared _composite_strip_onto_frame helper
- Fix rotation precision: snap trig values near 0/±1 to exact values,
use pixel-center convention (dim-1)/2, and parity-matched output buffers
- All 99 tests pass with zero pixel differences
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
