[vaprdev]

Summary

Night scenes were dark and murky, so silhouettes and creatures got lost. Each night now has clear light structure: a lighter horizon band for silhouettes to stand against, strong moonlit rims, and a few warm pools of light that ground and creatures pick up as they pass.

+src/light.ts
+  lightPool()      lights an ellipse in the light's own color
+  campfire()       logs and flickering flames, shared by desert and beach
+  fireflyLight()   the pool a firefly throws on leaves and grass
 desert       campfire
 beach        bonfire, stronger foam glow
 farm         open barn door, fireflies light the grass
 prehistoric  lava light on the ground
 tundra       igloo light on the snow
 city         skyglow behind the skyline, lamps light the sidewalk
 zen          lantern light on the bank
 jungle       brighter mist band, fireflies light the leaves
 space        airglow, planet-lit rims, amber lamps
 ocean        lighter water, rimmed silhouettes, plankton glow

The helpers are exported from the API and the night rules documented in CONTRIBUTING.

Evidence

Before (main) on the left, after on the right.

Verification: bun run typecheck passes; CI's check job runs dev/check.ts on this branch.

Merge Danger

Door: two-way

Blast Radius: visuals

Night looks of all ten wallpapers; the area behind text is kept no brighter than before.

Merged together with the other visual improvements in #1; this PR's CI screenshot check fails by design because screenshots are regenerated there.