Voice message: variable play back speed (#5121)

* Implement voice message variable playback speed

* Move playback speed string to Untranslated

https://github.com/element-hq/element-x-ios/pull/5121#discussion_r2822631371

* Address review feedback for voice message playback speed

- Persist voice message playback speed as an enum in AppSettings instead of storing an index.
- Update playback speed cycling to derive from enum allCases and safely fall back to `.default` if the stored value cannot be resolved.
- Apply runtime speed updates in AudioPlayer only when the player is in the `.playing` state.
- Keep MediaPlayerProviderTests formatting/indentation style intact while retaining mock playback speed setup.
- Regenerate preview snapshots for:
  - PlaybackSpeedButton
  - VoiceMessageRoomPlaybackView
  - VoiceMessageRoomTimelineView

* Move VoiceMessagePlaybackSpeed outside AppSettings, remove speedRatio

* Stabilize PlaybackSpeedButton width

* Sync voice-message speed label

- Add voiceMessagePlaybackSpeed to TimelineViewState and bind it from appSettings.$voiceMessagePlaybackSpeed.
- Pass that timeline-level speed into VoiceMessageRoomPlaybackView and use it for PlaybackSpeedButton, so labels update consistently across items.
- Use @EnvironmentObject in VoiceMessageRoomTimelineContent so the view re-renders when timeline context state changes.
- In WaveformInteractionModifier, add .allowsHitTesting(showCursor) to the cursor interaction view so hidden pre-playback cursor hit area does not steal taps from the speed button.

ElementX/Sources/Screens/Timeline/TimelineViewModel.swift

@@ -102,6 +102,7 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
                                                        isViewSourceEnabled: appSettings.viewSourceEnabled,
                                                        areThreadsEnabled: appSettings.threadsEnabled,
                                                        linkPreviewsEnabled: appSettings.linkPreviewsEnabled,
+                                                       voiceMessagePlaybackSpeed: appSettings.voiceMessagePlaybackSpeed.rawValue,
                                                        hasPredecessor: roomProxy.predecessorRoom != nil,
                                                        pinnedEventIDs: roomProxy.infoPublisher.value.pinnedEventIDs,
                                                        emojiProvider: emojiProvider,
@@ -370,6 +371,8 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
             Task { await timelineInteractionHandler.playPauseAudio(for: itemID) }
         case .seek(let itemID, let progress):
             Task { await timelineInteractionHandler.seekAudio(for: itemID, progress: progress) }
+        case .changePlaybackSpeed(let itemID):
+            timelineInteractionHandler.changePlaybackSpeed(for: itemID)
         }
     }
     
@@ -540,6 +543,11 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
         appSettings.$threadsEnabled
             .weakAssign(to: \.state.areThreadsEnabled, on: self)
             .store(in: &cancellables)
+
+        appSettings.$voiceMessagePlaybackSpeed
+            .map(\.rawValue)
+            .weakAssign(to: \.state.voiceMessagePlaybackSpeed, on: self)
+            .store(in: &cancellables)
         
         userSession.clientProxy.timelineMediaVisibilityPublisher
             .removeDuplicates()