[vaprdev]

Summary

Moving light (the aurora, campfires, lava, neon) only lit itself; nothing around it changed. src/lightmap.ts adds a low-resolution light map: scenes drop light nodes into a coarse grid each frame, and LightMap.apply() spreads it over the ground they light. firelight() gives fires a shared flicker and auroraFold() the aurora's travelling folds.

render()
  lights.clear()
  lights.node(i, j, color, strength, reach)   # aurora folds, fires, lava, neon, lanterns
  lights.apply(hdr)                           # blur the grid up and add it to the scene; touch() each lit run

• Tundra: the aurora's sheen moves across the snow and lake.
• Fires flicker (desert campfire, tundra igloos, farm barn door, zen lanterns); prehistoric lava glows on the slope; city neon lights the street.

Refinements:

• LightMap.apply() touches the runs of blocks it lights, so cells reused by dirty-cells pick up the moving light (--verify-dirty passes).
• The tundra aurora sheen on the snow is toned down by a quarter.

Evidence

After the refinements, previews behind text, origin/main (left) vs this branch (right):

Cost, dev/check.ts tundra desert prehistoric city back to back twice: 6.37 → 6.63 ms/frame. Worst flicker unchanged (86 cells).

Verified: typecheck, build, dev/check.ts --max-ms=60 in octant and quadrant mode (0 failed), --verify-dirty 90/90 with every lit pixel inside the touched boxes; screenshots regenerated.

Merge Danger

Door: two-way

Blast Radius: the look of night and sunset scenes with fires, lava, neon or aurora.