Add tvOS A/V sync diagnostics on its own settings page

Surface audio-delay (±10/±100 ms) and video-sync-mode controls behind an
"A/V Sync" navigation row in Advanced settings rather than inline, keeping the
Advanced page uncluttered. Audio delay applies live to the running MPV
instance; sync mode takes effect on next playback.

Yattee/Views/Settings/AdvancedSettingsView.swift

@@ -32,6 +32,9 @@ struct AdvancedSettingsView: View {
             #endif
             streamDetailsSection
             mpvSection
+            #if os(tvOS)
+            avSyncSection
+            #endif
             settingsSection
             #if !os(tvOS)
             downloadsStorageSection
@@ -230,6 +233,26 @@ struct AdvancedSettingsView: View {
         }
     }
 
+    #if os(tvOS)
+    @ViewBuilder
+    private var avSyncSection: some View {
+        if let settings = appEnvironment?.settingsManager {
+            SettingsFormSection {
+                NavigationLink {
+                    TVSidebarDetailContainer(
+                        systemImage: "wave.3.right",
+                        title: String(localized: "settings.playback.tvSyncDiagnostics.header")
+                    ) {
+                        AVSyncDiagnosticsView(settings: settings)
+                    }
+                } label: {
+                    Label(String(localized: "settings.playback.tvSyncDiagnostics.row"), systemImage: "wave.3.right")
+                }
+            }
+        }
+    }
+    #endif
+
     private static let mpvBufferOptions: [Double] = [1.0, 2.0, 3.0, 4.0, 5.0]
 
     private func formatBufferOption(_ seconds: Double) -> String {