[vaprdev]

Summary

In low-contrast cells (glows, haze, sky gradients) the free two-color fit picked whatever octant pattern happened to fit best, so soft light came out as speckle. bandSplit() now gives those cells a split aligned with the gradient: halves, quarters or a middle stripe, kept with the same hysteresis as other splits.

 writeOctant / writeQuadrant(cell)
+  band = bandSplit(cell)       # only when the cell is soft (flat fit error under SOFT)
+  if band fits nearly as well as the free split → draw the band
   otherwise → best free split

Evidence

Reference (scene, brightened) | before (origin/main) | after:

Cost, dev/check.ts tundra ocean city jungle back to back twice: 7.20 → 7.40 ms/frame. Worst flicker 83 → 87 cells (limit 150).

Verified: typecheck, build, dev/check.ts --max-ms=60 in octant and quadrant mode (0 failed), --verify-dirty 90/90, screenshots up to date.

Merge Danger

Door: two-way

Blast Radius: glyphs in soft cells of every wallpaper.