Disable editor network bootstrap in builds; tune scenes and paint HUD panel

NetworkBootstrap now destroys itself outside the editor. Camera FOV/background
tweaks in Main, lobby light intensity, and paint HUD panel font/color polish.

Assets/Scenes/Main.unity

@@ -468,7 +468,7 @@ MonoBehaviour:
     LookAtTarget: {fileID: 0}
     CustomLookAtTarget: 0
   Lens:
-    FieldOfView: 45
+    FieldOfView: 48
     OrthographicSize: 10
     NearClipPlane: 0.1
     FarClipPlane: 5000
@@ -739,7 +739,7 @@ Camera:
   m_Enabled: 1
   serializedVersion: 2
   m_ClearFlags: 1
-  m_BackGroundColor: {r: 0.13333334, g: 0.2, b: 0.26666668, a: 0}
+  m_BackGroundColor: {r: 0, g: 0, b: 0, a: 0}
   m_projectionMatrixMode: 1
   m_GateFitMode: 2
   m_FOVAxisMode: 0
@@ -762,7 +762,7 @@ Camera:
     height: 1
   near clip plane: 0.1
   far clip plane: 5000
-  field of view: 45
+  field of view: 48
   orthographic: 0
   orthographic size: 10
   m_Depth: -1
@@ -948,7 +948,7 @@ MonoBehaviour:
     LookAtTarget: {fileID: 0}
     CustomLookAtTarget: 0
   Lens:
-    FieldOfView: 45
+    FieldOfView: 52
     OrthographicSize: 10
     NearClipPlane: 0.1
     FarClipPlane: 5000
@@ -1240,7 +1240,7 @@ MonoBehaviour:
   m_Name: 
   m_EditorClassIdentifier: UnityEngine.UI::UnityEngine.UI.RawImage
   m_Material: {fileID: 0}
-  m_Color: {r: 0.26415092, g: 0.26415092, b: 0.26415092, a: 1}
+  m_Color: {r: 0.60784316, g: 0.60784316, b: 0.60784316, a: 0.60784316}
   m_RaycastTarget: 1
   m_RaycastPadding: {x: 0, y: 0, z: 0, w: 0}
   m_Maskable: 1
@@ -1670,7 +1670,7 @@ MonoBehaviour:
     LookAtTarget: {fileID: 0}
     CustomLookAtTarget: 0
   Lens:
-    FieldOfView: 45
+    FieldOfView: 48
     OrthographicSize: 10
     NearClipPlane: 0.1
     FarClipPlane: 5000