Add tvOS display frame rate and dynamic range matching

Lets the Apple TV switch its HDMI output to match the playing video's
frame rate and dynamic range via AVDisplayManager.preferredDisplayCriteria,
driven from MPV's container-fps and video-params/gamma. Two opt-in toggles
(default off) live under Playback → Display on tvOS; both are no-ops on
other platforms. Anchor an AVKit class symbol so the linker keeps AVKit
linked — Swift only autolinks AVFoundation here, and without AVKit the
UIWindow.avDisplayManager category isn't loaded at runtime.

Yattee/Core/Settings/SettingsKey.swift

@@ -108,6 +108,8 @@ enum SettingsKey: String, CaseIterable {
     case mpvBufferSeconds
     case mpvUseEDLStreams
     case zoomTransitionsEnabled
+    case tvMatchDisplayFrameRate
+    case tvMatchDisplayDynamicRange
 
     // Details panel
     case floatingDetailsPanelSide // Landscape only - which side the panel appears on

Yattee/Core/Settings/SettingsManager+Advanced.swift

@@ -141,6 +141,36 @@ extension SettingsManager {
         }
     }
 
+    /// Whether tvOS should request the Apple TV switch its HDMI output to match the
+    /// playing video's frame rate. Has no effect unless the user also enables
+    /// "Match Content → Frame Rate" in tvOS Settings → Video and Audio.
+    /// Default is true on tvOS (no-op on other platforms).
+    var tvMatchDisplayFrameRate: Bool {
+        get {
+            if let cached = _tvMatchDisplayFrameRate { return cached }
+            return bool(for: .tvMatchDisplayFrameRate, default: false)
+        }
+        set {
+            _tvMatchDisplayFrameRate = newValue
+            set(newValue, for: .tvMatchDisplayFrameRate)
+        }
+    }
+
+    /// Whether tvOS should request the Apple TV switch its HDMI output to match the
+    /// playing video's dynamic range (SDR / HDR10 / HLG). Has no effect unless the
+    /// user also enables "Match Content → Dynamic Range" in tvOS Settings.
+    /// Default is true on tvOS (no-op on other platforms).
+    var tvMatchDisplayDynamicRange: Bool {
+        get {
+            if let cached = _tvMatchDisplayDynamicRange { return cached }
+            return bool(for: .tvMatchDisplayDynamicRange, default: false)
+        }
+        set {
+            _tvMatchDisplayDynamicRange = newValue
+            set(newValue, for: .tvMatchDisplayDynamicRange)
+        }
+    }
+
     /// Whether zoom navigation transitions are enabled (iOS only).
     /// When enabled, navigating to video/channel/playlist details shows a zoom animation
     /// from the source thumbnail. Disable if experiencing visual glitches with swipe-back gestures.

Yattee/Core/SettingsManager.swift

@@ -158,6 +158,8 @@ final class SettingsManager {
     var _mpvBufferSeconds: Double?
     var _mpvUseEDLStreams: Bool?
     var _zoomTransitionsEnabled: Bool?
+    var _tvMatchDisplayFrameRate: Bool?
+    var _tvMatchDisplayDynamicRange: Bool?
 
     // Details panel settings
     var _floatingDetailsPanelSide: FloatingPanelSide?
@@ -492,6 +494,8 @@ final class SettingsManager {
         _mpvBufferSeconds = nil
         _mpvUseEDLStreams = nil
         _zoomTransitionsEnabled = nil
+        _tvMatchDisplayFrameRate = nil
+        _tvMatchDisplayDynamicRange = nil
         _floatingDetailsPanelSide = nil
         _floatingDetailsPanelWidth = nil
         _landscapeDetailsPanelVisible = nil