Three coordinated changes:
1. nightPaletteNew.cloud: void -> raised (slightly lighter than
sky) so clouds have contrast against the new-moon sky
2. nightPaletteFull.cloudShadow: panel -> void so cloud undersides
fade into the night sky, while the lit topsides (border) stand
out clearly
3. getNightColor() now keeps 'light' (moonlight) bright and only
partially darkens sky/bg. The previous version squashed
everything toward black, killing cloud structure.
Shader side:
- max(0.15, uDayProgress) keeps a baseline moonlight tint on the
lit side of clouds even when uDayProgress happens to be 0
- The final darken pass is now driven by nightFactor (sunAlt-based)
instead of the unreliable uDayProgress