experiment(PodcastPlayerView): add playbackSpeed control (0.75×/1×/1.25×/1.5×/2×) with menu

Marks/Views/PodcastPlayerView.swift

@@ -42,6 +42,9 @@ final class PodcastPlayerViewModel {
     var duration: Double = 1
     var currentArticleUrl: String = ""
     var currentArticleTitle: String = ""
+    var playbackSpeed: Float = 1.0
+
+    static let availableSpeeds: [Float] = [0.75, 1.0, 1.25, 1.5, 2.0]
 
     var isGenerating: Bool {
         switch phase {
@@ -135,7 +138,11 @@ final class PodcastPlayerViewModel {
 
     func togglePlayPause() {
         guard let player else { return }
-        if isPlaying { player.pause() } else { player.play() }
+        if isPlaying {
+            player.pause()
+        } else {
+            player.rate = playbackSpeed
+        }
         isPlaying.toggle()
         updateNowPlaying()
     }
@@ -154,6 +161,12 @@ final class PodcastPlayerViewModel {
         seek(to: max(currentTime - 15, 0))
     }
 
+    func setPlaybackSpeed(_ speed: Float) {
+        playbackSpeed = speed
+        if isPlaying { player?.rate = speed }
+        updateNowPlaying()
+    }
+
     private func setupPlayer(url: URL, title: String) {
         currentPodcastTitle = title
 
@@ -205,7 +218,7 @@ final class PodcastPlayerViewModel {
         setupRemoteCommands()
         phase = .ready(title: title)
         updateNowPlaying()
-        p.play()
+        p.rate = playbackSpeed
         isPlaying = true
     }
 
@@ -384,6 +397,29 @@ struct PodcastPlayerView: View {
                         .foregroundStyle(.primary)
                 }
             }
+
+            Menu {
+                ForEach(PodcastPlayerViewModel.availableSpeeds, id: \.self) { speed in
+                    Button {
+                        vm.setPlaybackSpeed(speed)
+                    } label: {
+                        let label = speed == 1.0 ? "1× (Normal)" : "\(String(format: "%g", speed))×"
+                        if speed == vm.playbackSpeed {
+                            Label(label, systemImage: "checkmark")
+                        } else {
+                            Text(label)
+                        }
+                    }
+                }
+            } label: {
+                Text(vm.playbackSpeed == 1.0 ? "1× Speed" : "\(String(format: "%g", vm.playbackSpeed))×")
+                    .font(.system(size: 14, weight: .semibold))
+                    .foregroundStyle(.secondary)
+                    .padding(.horizontal, 14)
+                    .padding(.vertical, 7)
+                    .background(Color(.systemGray5))
+                    .clipShape(Capsule())
+            }
         }
     }