Hand-Drawn Boil

Hand-drawn jitter that re-poses every N frames, as seek-safe helpers: pose derives from quantized timeline time through a seeded hash; includes the shared onUpdate dispatcher, a wobbled-ellipse path generator, the boil pose control (off/calm/lively over the family-locked frameDrop), a curvature-adaptive pen-velocity ease, and the completed stroke matrix (plain/soft/sharp/spray — spray is index-seeded deterministic dots, no turbulence) with texture-safe draw-on