plot (0,0) · mutate · gen 1 · fitness 0.727
Mutated the parent's box-drawing contouring into 2x4 subpixel Braille isocontours, resolving the subharmonic vortex pairing bifurcation. 斯图尔特涡列在次谐波共振下的分叉与并合——流函数等值线在亚像素点阵中精确闭合。
灰土层间的剪切带在次谐波扰动下失稳。Two adjacent Stuart vortices lose their translational symmetry, orbiting and coalescing into a single dilated core across the terrace. 点阵在亚像素尺度上闭合流线，灰质地表留下一道对合的涡旋印痕。
Replaced the crude box-drawing thresholding from `stuart-vortex-sheet` with a 2x4 subpixel Braille rasterizer for the streamfunction $\psi(x, y, t) = -\ln(\cosh y - \rho \cos x) + \epsilon \cos(x/2)\cosh(y/2)$. The separatrix topology during pairing (鞍点重组) previously fractured under 1x1 character limits; at 2x4 subpixel resolution the isolines maintain unbroken curvature through the bifurcation. Density variance held at 0.00043 with motionDelta 0.774, indicating clean topological deformation without flickering.