Fix picker label visibility on macOS in settings

Add visible labels for all pickers in settings on macOS by wrapping them
in HStack with Text labels and Spacer() for proper alignment.

Fixed pickers:
- BrowsingSettings: Startup section, Thumbnails quality, Player bar gestures
- PlayerControlsSettings: Action button labels
- PlayerSettings: Source, Inspector, Caption size/color/languages, Sidebar

All picker labels now consistently display with left-aligned text and
right-aligned picker controls on macOS.

Shared/Settings/PlayerControlsSettings.swift

@@ -132,12 +132,25 @@ struct PlayerControlsSettings: View {
         }
 
         Section {
-            Picker("Action button labels", selection: $playerActionsButtonLabelStyle) {
-                ForEach(ButtonLabelStyle.allCases, id: \.rawValue) { style in
-                    Text(style.description).tag(style)
+            #if os(macOS)
+                HStack {
+                    Text("Action button labels")
+                    Spacer()
+                    Picker("Action button labels", selection: $playerActionsButtonLabelStyle) {
+                        ForEach(ButtonLabelStyle.allCases, id: \.rawValue) { style in
+                            Text(style.description).tag(style)
+                        }
+                    }
+                    .modifier(SettingsPickerModifier())
                 }
-            }
-            .modifier(SettingsPickerModifier())
+            #else
+                Picker("Action button labels", selection: $playerActionsButtonLabelStyle) {
+                    ForEach(ButtonLabelStyle.allCases, id: \.rawValue) { style in
+                        Text(style.description).tag(style)
+                    }
+                }
+                .modifier(SettingsPickerModifier())
+            #endif
         }
     }