Fur: Albedo-gekoppelte Länge, Toggle-Gate, Soft-Edge, World-Gravity, Pipette & FP-Hide

- Fur-Map trägt nur noch R = Länge (linearer Datenkanal); Farbe kommt per-texel
  aus der Live-Albedo-RT (an _BaseMap des Shell-Shaders gebunden)
- Toggle_Fur als echtes Gate (IsChannelActive = fur), Default aus, furLength 0.5
- Weicher Alpha-Übergang (radial/tip/length coverage) statt Hard-Clip; Transparent-
  Pass mit Depth-Bias (Offset -1,-1) gegen Body-Durchflimmern
- Root dunkler / Tip heller aus gemalter Farbe abgeleitet (kein Fix-Tint)
- Gravity/Curl in World-Space nach Transform (unabhängig von Mesh-Rotation)
- Pipette aktiviert Fur-Toggle immer; liest R-Kanal als Länge
- First-Person blendet FurShellRenderer mit aus
- Netzwerk (FlagFur), Undo, Persistence (fur.png R=Länge) mitgezogen

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/Scripts/Components/UI/PaintHud/PaintHud.Persistence.cs

@@ -20,7 +20,9 @@ public partial class PaintHud
              "defaults every session.")]
     public bool persistHud = true;
 
-    private const int HudFileVersion = 1;
+    // v2: HudValues gained fur (toggle) + furLength. Bumping discards pre-v2 saves so the new fur fields
+    // fall back to the painter's prefab defaults instead of deserializing as 0/false.
+    private const int HudFileVersion = 2;
 
     // Auto-save bookkeeping. Brush edits are debounced (sliders fire every frame while dragged): the due
     // time is pushed forward and written once they settle.
@@ -83,11 +85,12 @@ public partial class PaintHud
     [Serializable]
     private class HudValues
     {
-        public bool paintAlbedo, paintMetallicSmoothness, paintOcclusion, paintEmission, spray;
+        public bool paintAlbedo, paintMetallicSmoothness, paintOcclusion, paintEmission, spray, fur;
         public Color brushColor;
         public float metallic, smoothness, metallicSmoothnessOpacity, occlusion, occlusionOpacity;
         public Color emissionColor;
         public float emissionIntensity;
+        public float furLength;
         public int brushSize;
         public int activeBrushIndex;
         public int sprayDots;
@@ -275,6 +278,8 @@ public partial class PaintHud
             && p.paintOcclusion == v.paintOcclusion
             && p.paintEmission == v.paintEmission
             && p.spray == v.spray
+            && p.fur == v.fur
+            && p.furLength == v.furLength
             && p.brushColor == v.brushColor
             && p.metallic == v.metallic
             && p.smoothness == v.smoothness
@@ -335,6 +340,8 @@ public partial class PaintHud
         v.paintOcclusion = from.paintOcclusion;
         v.paintEmission = from.paintEmission;
         v.spray = from.spray;
+        v.fur = from.fur;
+        v.furLength = from.furLength;
         v.brushColor = from.brushColor;
         v.metallic = from.metallic;
         v.smoothness = from.smoothness;
@@ -371,6 +378,8 @@ public partial class PaintHud
         to.paintOcclusion = v.paintOcclusion;
         to.paintEmission = v.paintEmission;
         to.spray = v.spray;
+        to.fur = v.fur;
+        to.furLength = v.furLength;
         to.brushColor = v.brushColor;
         to.metallic = v.metallic;
         to.smoothness = v.smoothness;