Rakoun: DarkFantasy Visuals

## v2.6.0 — Atmospheric Clarity

  The image stops going milky, and the rain finally touches the ground.

  ### New: local contrast
  - When light shafts, bloom and volumetric mist pile up (stained glass rooms, hazy vistas), the image used to flatten into a milky wash — a global tonemap simply cannot fix that. Local contrast now restores the texture: it works on luminance in the log domain, so bright lanterns on a dark night don't smear halos, and it never touches your colors.
  - Soft-clamped to avoid ringing around bright sources. Off at strength 1.0, which is a bit-exact identity.
  - Costs essentially nothing: it reuses the mip chain the auto-exposure already builds.
  - Strength, scale and halo limit are all in the Post menu, with a debug view to tune them.

  ### New: procedural rain impacts
  - Minecraft's rain splash particles — those opaque blue cubes — are gone. In their place, real impacts drawn by the shader.
  - Two behaviours, because physics: a drop landing in a PUDDLE spreads a ripple (a thin ring that is born, expands and dies in a third of a second); a drop landing on WET STONE doesn't spread anything — it just splashes.
  - The rings distort the REFLECTIONS: the lantern reflected in a puddle now trembles as the impacts cross it. The ground stays perfectly readable underneath — this is water, it bends what's below, it doesn't paint over it.
  - At night, impacts spark briefly under nearby lights — in the light's own color (blue under a soul lantern).
  - Density, size and strength in the Ambience menu. The dry splash can be turned off (and is, in the Performance profile).