Haste v22 - Underwater Balance Rework (development build)

Changes
- Rebalanced underwater rays after v20 produced broad, over-bright blue bands and v21 made them too faint.
- Uses screen-space depth marching when the sun is visible, plus a medium-width, softly broken world-space fallback when looking down or when the sun is off-screen.
- Moderate additive shaft energy avoids painting opaque blue ribbons over the scene.
- Reduced underwater absorption and fog density, while retaining distance-based red-first attenuation and protection for emissive/local-lit pixels.
- Reduced preset darkness defaults progressively from Hastefull to Ethereal; users can still increase Underwater Darkness in Water & Reflections.

Performance
- No new render targets, samplers, or passes.
- Keeps the existing per-preset UNDERWATER_RAY_QUALITY depth samples.
- Hastefull retains four screen-space ray samples; the off-screen fallback uses fixed math only.

Validation
- ZIP integrity and structural checks performed: balanced braces/preprocessor directives, one definition per underwater ray function, and the intended profile values are present.
- Not compiled or runtime-tested in Minecraft + Sodium + Iris in this environment; visual result and FPS still require in-game testing.
