Authoring: radar scene setup, materials, tag + fur/probuilder tweaks

- Main.unity: Radar / Target Template / Point hierarchy under Radar Camera
- Radar tag added (TagManager)
- Radar.mat + RadarPoint.mat (URP Particles/Unlit blip material)
- The Room.unity: fur shader tint/softness tweaks, Target Template disabled
- Player.prefab: xrayFlashBoost/fur field reserialization
- ProBuilder editor prefs

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

Assets/Prefabs/Player.prefab

@@ -485,6 +485,7 @@ MonoBehaviour:
   sprayDotAlphaMax: 1
   maxUndoSteps: 20
   xrayFadeDuration: 0.15
+  xrayFlashBoost: 3
   useGpu: 1
   paintAlbedo: 1
   paintMetallicSmoothness: 0
@@ -498,6 +499,7 @@ MonoBehaviour:
   occlusionOpacity: 1
   emissionColor: {r: 1, g: 0.6, b: 0, a: 1}
   emissionIntensity: 20
+  fur: 0
   furLength: 0.5
   brushSize: 50
   brushSizeScrollFactor: 0.15