Force plain list style on tvOS and hide setting from appearance

Inset/grouped list style doesn't work well with tvOS focus effects.
Always return .plain on tvOS and hide the list style picker from
appearance settings.

Yattee/Core/Settings/SettingsManager+Advanced.swift

@@ -208,6 +208,9 @@ extension SettingsManager {
     /// Default is plain. Synced per-platform via iCloud.
     var listStyle: VideoListStyle {
         get {
+            #if os(tvOS)
+            return .plain
+            #else
             if let cached = _listStyle { return cached }
             guard let rawValue = string(for: .listStyle),
                   let style = VideoListStyle(rawValue: rawValue) else {
@@ -215,6 +218,7 @@ extension SettingsManager {
             }
             _listStyle = style
             return style
+            #endif
         }
         set {
             _listStyle = newValue

Yattee/Views/Settings/AppearanceSettingsView.swift

@@ -29,7 +29,9 @@ struct AppearanceSettingsView: View {
                 #endif
 
                 // List style section
+                #if !os(tvOS)
                 ListStyleSection(settings: settings)
+                #endif
 
                 // Thumbnail section
                 ThumbnailSection(settings: settings)