HASTE v29
- Underwater haze made much denser (density ~0.018+0.010*darkness per block x Water Murk, was ~0.004): visibility ~60 blocks at default.
- Sky/horizon pixels fully fog out. Shafts now also attenuate with the haze. Water Murk default 1.0 (range 0.5-2.0).
Compiled with glslang only; not tested in-game.

Follow-up in v30: added an independent Underwater Distance Fog toggle and adjustable start distance.
