Add per-page element customization and panel settings polish

Phase 5 of the player panels redesign:
- Per-page element toggles now rendered and editable for every page:
  comments (author avatars), related (thumbnails), chapters (thumbnails),
  queue (previously played section), tracks (video/audio/subtitles/speed
  sections)
- Page bar labels toggle (icons-only bar shows the selected page's name)
- Layout mode schematic diagram in the details panel settings
- NEW badge machinery for future page types (versionAdded on PanelPageType)
- Typed per-page settings accessors on PanelPageConfiguration and VM update
  helpers for each page kind
- Unit tests for per-page settings round-trip and accessor fallbacks

The standalone quality selector sheet is unaffected: section gating defaults
to everything visible and only the embedded tracks page passes preset
settings through.

Yattee/Views/Components/CommentView.swift

@@ -15,6 +15,7 @@ struct CommentView: View {
     let videoID: String?
     let source: ContentSource?
     let isReply: Bool
+    let showAvatar: Bool
 
     @State private var replies: [Comment] = []
     @State private var isLoadingReplies = false
@@ -26,18 +27,21 @@ struct CommentView: View {
     private var navigationCoordinator: NavigationCoordinator? { appEnvironment?.navigationCoordinator }
     private var accentColor: Color { appEnvironment?.settingsManager.resolvedAccentColor ?? .accentColor }
 
-    init(comment: Comment, videoID: String? = nil, source: ContentSource? = nil, isReply: Bool = false) {
+    init(comment: Comment, videoID: String? = nil, source: ContentSource? = nil, isReply: Bool = false, showAvatar: Bool = true) {
         self.comment = comment
         self.videoID = videoID
         self.source = source
         self.isReply = isReply
+        self.showAvatar = showAvatar
     }
 
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {
             HStack(alignment: .top, spacing: 12) {
                 // Author avatar
-                authorAvatar
+                if showAvatar {
+                    authorAvatar
+                }
 
                 VStack(alignment: .leading, spacing: 4) {
                     // Author name and badges
@@ -224,7 +228,7 @@ struct CommentView: View {
             if showReplies {
                 VStack(alignment: .leading, spacing: 0) {
                     ForEach(replies) { reply in
-                        CommentView(comment: reply, source: source, isReply: true)
+                        CommentView(comment: reply, source: source, isReply: true, showAvatar: showAvatar)
                             .padding(.leading, 44)
 
                         if reply.id != replies.last?.id {

Yattee/Views/Components/ExpandedCommentsView.swift

@@ -255,6 +255,7 @@ struct CommentsListContent: View {
     @Environment(\.appEnvironment) private var appEnvironment
 
     let videoID: String
+    var showAvatars: Bool = true
 
     private var playerState: PlayerState? { appEnvironment?.playerService.state }
     private var contentService: ContentService? { appEnvironment?.contentService }
@@ -318,7 +319,7 @@ struct CommentsListContent: View {
             } else {
                 LazyVStack(alignment: .leading, spacing: 0) {
                     ForEach(comments) { comment in
-                        CommentView(comment: comment, videoID: videoID, source: videoSource)
+                        CommentView(comment: comment, videoID: videoID, source: videoSource, showAvatar: showAvatars)
                             .onAppear {
                                 if comment.id == comments.last?.id,
                                    playerState?.commentsContinuation != nil,

Yattee/Views/Components/VideoRowView.swift

@@ -26,6 +26,8 @@ struct VideoRowView: View {
     var index: Int? = nil
     /// When true, disables internal tap handling so parent view can handle all taps.
     var disableInternalTapHandling: Bool = false
+    /// When false, hides the thumbnail (e.g. details panel related page setting).
+    var showThumbnail: Bool = true
 
     // Platform-specific fonts
     #if os(tvOS)
@@ -95,8 +97,10 @@ struct VideoRowView: View {
             }
             
             // Thumbnail
-            thumbnailView
-                .zoomTransitionSource(id: video.id)
+            if showThumbnail {
+                thumbnailView
+                    .zoomTransitionSource(id: video.id)
+            }
 
             // Info
             infoView