Netcode: receiver-side paint reveal gate + fur pipette gating

Hide remote avatars until this client has actually applied a snapshot
reaching the owner-published baseline cutoff, preventing the default
grey/white material from flashing before a player's painting has loaded.

- PlayerPaintSync: owner-authoritative _publishedCutoff NetworkVariable,
  receiver tracks _appliedCutoff; explicit blank publish for never-painted
  avatars so they still reveal.
- NetworkPlayerSetup: cache _paintSync, hide body renderers on spawn, gate
  UpdateVisibility on PaintRevealReady.
- MeshPainter.Pick: fur toggle now follows pickedHeight (own paint-mesh
  only), matching the Occlusion/Height pipette behaviour.

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

Assets/Scripts/Components/MeshPainter/MeshPainter.Pick.cs

@@ -8,8 +8,9 @@ public partial class MeshPainter
     [Header("Brush - pipette (eyedropper)")]
     [Tooltip("Pipette mode: a click samples the channel values at the hit point on ANY surface " +
              "(albedo, metallic, smoothness, emission) and adopts them into the brush (opacities/alphas " +
-             "left untouched) instead of painting. Height (occlusion) is adopted and its toggle enabled " +
-             "only when our own paint mesh is picked; any other surface disables the height toggle. On a " +
+             "left untouched) instead of painting. Height (occlusion) and fur length are adopted and their " +
+             "toggles enabled only when our own paint mesh is picked; any other surface disables those " +
+             "toggles and keeps their values. On a " +
              "foreign object the data channels are read texel-exact from the material; albedo follows " +
              "'Pipette Albedo From Screen'. Held button picks once.")]
     public bool pipette = false;
@@ -84,9 +85,10 @@ public partial class MeshPainter
         paintMetallicSmoothness = true;
         paintOcclusion = pickedHeight;
         paintEmission = true;
-        // Fur toggle always turns on with a pick; the length is only adopted off our own paint mesh
-        // (pickedHeight), so a foreign-surface pick enables fur but leaves furLength at its current value.
-        fur = true;
+        // Fur mirrors height/occlusion: adopted and its toggle enabled only when our OWN paint mesh was
+        // picked (pickedHeight, where furLength was sampled); any other surface disables the fur toggle
+        // and keeps furLength.
+        fur = pickedHeight;
 
         pipette = false;