Switch to Deferred+ with dedicated forward renderer for radar camera; rendering-layer setup across scenes

Also serializes wallStepOffset on Player prefab and includes SliderDoubleClickReset wiring in Main (mixed scene edits).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/Scenes/Lobby.unity

@@ -1054,7 +1054,7 @@ MonoBehaviour:
   m_SoftShadowQuality: 0
   m_RenderingLayersMask:
     serializedVersion: 0
-    m_Bits: 1
+    m_Bits: 3
   m_ShadowRenderingLayersMask:
     serializedVersion: 0
     m_Bits: 1
@@ -1112,7 +1112,7 @@ Light:
   m_CullingMask:
     serializedVersion: 2
     m_Bits: 4294967295
-  m_RenderingLayerMask: 1
+  m_RenderingLayerMask: 3
   m_Lightmapping: 4
   m_LightShadowCasterMode: 0
   m_AreaSize: {x: 1, y: 1}