Drive macOS player control bars from presets

Render the macOS control bar button row and top bar from the active
preset's sections via a new MacOSControlsSectionRenderer, replacing the
hardcoded QuickTime-style rows in MacOSControlBar. Add a keepOnTop
button type and macOS-specific button availability lists, and adapt the
player controls settings editors (preset editor, section editor, button
configuration) for macOS.

Also apply the preset font style to the control bar time labels, and
update the built-in macOS Default preset order (queue before transport,
fullscreen at the end), bumping builtInPresetsVersion to 7.

Yattee/Views/Settings/PlayerControls/CenterControlsSettingsView.swift

@@ -20,8 +20,28 @@ struct CenterControlsSettingsView: View {
     @State private var leftSlider: SideSliderType = .disabled
     @State private var rightSlider: SideSliderType = .disabled
 
+    /// On macOS the center overlay doesn't exist; the seek durations always
+    /// apply (keyboard arrows and default seek buttons), so the controls are
+    /// always visible there.
+    private var seekBackwardControlsVisible: Bool {
+        #if os(macOS)
+        return true
+        #else
+        return showSeekBackward
+        #endif
+    }
+
+    private var seekForwardControlsVisible: Bool {
+        #if os(macOS)
+        return true
+        #else
+        return showSeekForward
+        #endif
+    }
+
     var body: some View {
         Form {
+            #if os(iOS)
             // Preview
             Section {
                 CenterPreviewView(
@@ -47,9 +67,11 @@ struct CenterControlsSettingsView: View {
             } header: {
                 Text(String(localized: "settings.playerControls.center.playback"))
             }
+            #endif
 
             // Seek backward settings
             Section {
+                #if os(iOS)
                 Toggle(
                     String(localized: "settings.playerControls.center.showSeekBackward"),
                     isOn: $showSeekBackward
@@ -57,8 +79,9 @@ struct CenterControlsSettingsView: View {
                 .onChange(of: showSeekBackward) { _, newValue in
                     viewModel.updateCenterSettingsSync { $0.showSeekBackward = newValue }
                 }
+                #endif
 
-                if showSeekBackward {
+                if seekBackwardControlsVisible {
                     #if !os(tvOS)
                     HStack {
                         Text(String(localized: "settings.playerControls.center.seekBackwardTime"))
@@ -97,6 +120,7 @@ struct CenterControlsSettingsView: View {
 
             // Seek forward settings
             Section {
+                #if os(iOS)
                 Toggle(
                     String(localized: "settings.playerControls.center.showSeekForward"),
                     isOn: $showSeekForward
@@ -104,8 +128,9 @@ struct CenterControlsSettingsView: View {
                 .onChange(of: showSeekForward) { _, newValue in
                     viewModel.updateCenterSettingsSync { $0.showSeekForward = newValue }
                 }
+                #endif
 
-                if showSeekForward {
+                if seekForwardControlsVisible {
                     #if !os(tvOS)
                     HStack {
                         Text(String(localized: "settings.playerControls.center.seekForwardTime"))
@@ -140,6 +165,13 @@ struct CenterControlsSettingsView: View {
                 }
             } header: {
                 Text(String(localized: "settings.playerControls.center.seekForward"))
+            } footer: {
+                #if os(macOS)
+                Text(String(
+                    localized: "settings.playerControls.center.seekDurationsFooter",
+                    defaultValue: "Seek durations are used by the ← and → keyboard shortcuts and by seek buttons added to the player."
+                ))
+                #endif
             }
 
             #if os(iOS)
@@ -175,7 +207,12 @@ struct CenterControlsSettingsView: View {
             }
             #endif
         }
+        #if os(macOS)
+        .formStyle(.grouped)
+        .navigationTitle(String(localized: "settings.playerControls.seekDurations", defaultValue: "Seek Durations"))
+        #else
         .navigationTitle(String(localized: "settings.playerControls.centerControls"))
+        #endif
         #if os(iOS)
         .navigationBarTitleDisplayMode(.inline)
         #endif