Improve playback settings UI controls on macOS

Standardized picker and button sizing with consistent alignment and control sizes. Added SettingsPickerModifier to all macOS pickers with menu style. Improved rate buttons with proper sizing and alignment. Added text truncation for stream descriptions to prevent overflow.

Shared/Player/StreamControl.swift

@@ -20,7 +20,12 @@ struct StreamControl: View {
 
                         ForEach(kinds, id: \.self) { key in
                             ForEach(availableStreamsByKind[key] ?? []) { stream in
-                                Text(stream.description).tag(Stream?.some(stream))
+                                Text(stream.description)
+                                    #if os(macOS)
+                                    .lineLimit(1)
+                                    .truncationMode(.middle)
+                                    #endif
+                                    .tag(Stream?.some(stream))
                             }
 
                             #if os(macOS)
@@ -36,6 +41,8 @@ struct StreamControl: View {
                     .frame(minWidth: 110)
                     .fixedSize(horizontal: true, vertical: true)
                     .disabled(player.isLoadingAvailableStreams)
+                #elseif os(macOS)
+                    .fixedSize()
                 #endif
             #else
                 ControlsOverlayButton(focusedField: focusedField!, field: .stream) {