feat: redesign player with Dynamic Island, compact timer, and fix Live Activity timer drift

## What changed

### Player Redesign (video-first layout)
- New compact timer ring (110pt) with phase label, replaces 240pt ring
- Auto-hide top bar with block progress dots (3s auto-dismiss)
- Expandable now-playing music pill with skip control
- Bottom control bar with heart rate, play/pause, and skip
- Exercise caption with 'Next' preview during rest phases
- Compact round counter (capsule dots)

### Dynamic Island & Live Activities
- WorkoutLiveActivity widget: expanded, compact, and minimal views
- Phase-colored timers with Text(timerInterval:) countdown
- Shows exercise name, round progress, heart rate, music track
- MusicLiveActivity: standalone music now-playing widget
- LiveActivityMusicBars animated component
- Deep link from Dynamic Island back to app

### Timer Drift Fix (critical)
- Store a stable phaseEndDate once per phase instead of
  recalculating Date() + timeRemaining on every update
- Prevents dynamic island countdown from rubber-banding
  due to 5-second periodic update recalculation drift
- Reset phaseEndDate on phase change and resume from pause
- Guard Live Activity updates behind vm.isRunning to prevent
  premature creation when music track loads before workout start
- Fixes timer showing 0 in Dynamic Island when expanding
  from home screen

### New PlayerViewModel timer engine
- Full phase support: prep, warmup, work, rest,
  interBlockRest, cooldown, complete
- 1-second countdown with audio cues at 3-2-1
- Phase transitions with spring animation and haptics
- HealthKit live session integration
- Workout session recording with completion

### Music Service
- New MusicPlayerViewModel with vibe-based playlist loading
- Track info exposed for Dynamic Island display
- Skip track support from Dynamic Island notification action
- Automatic play/pause based on phase and running state

### Additional
- ZoneHighlightIcon component for HomeTab zone cards
- Updated watchOS localizations with complication strings
- Info.plist updated for widget extension

tabatago-swift/TabataGoWidget/MusicLiveActivity.swift

@@ -0,0 +1,135 @@
+import ActivityKit
+import WidgetKit
+import SwiftUI
+import AppIntents
+
+struct SkipTrackIntent: AppIntent {
+    static let title: LocalizedStringResource = "Skip Track"
+
+    @MainActor
+    func perform() async throws -> some IntentResult & OpensIntent {
+        let url = URL(string: "tabatago://skipTrack")!
+        return .result(opensIntent: OpenURLIntent(url))
+    }
+}
+
+struct MusicLiveActivity: Widget {
+    var body: some WidgetConfiguration {
+        ActivityConfiguration(for: MusicActivityAttributes.self) { context in
+            // ── Lock Screen / Banner ───────────────────
+            VStack(spacing: 0) {
+                HStack(spacing: 10) {
+                    Image(systemName: "music.note")
+                        .font(.title3.weight(.semibold))
+                        .foregroundStyle(.green)
+
+                    VStack(alignment: .leading, spacing: 2) {
+                        Text(context.state.title)
+                            .font(.headline)
+                            .foregroundStyle(.primary)
+                            .lineLimit(1)
+                        Text(context.state.artist)
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                            .lineLimit(1)
+                    }
+
+                    Spacer()
+
+                    if context.state.isPlaying {
+                        LiveActivityMusicBars()
+                    }
+                }
+                .padding(.horizontal, 16)
+                .padding(.vertical, 12)
+            }
+            .activityBackgroundTint(.black.opacity(0.9))
+            .activitySystemActionForegroundColor(.white)
+
+        } dynamicIsland: { context in
+            DynamicIsland {
+                // ── Expanded ────────────────────────────
+                DynamicIslandExpandedRegion(.leading) {
+                    HStack(spacing: 6) {
+                        Image(systemName: "music.note")
+                            .foregroundStyle(.green)
+                        Text(context.state.title)
+                            .font(.caption.weight(.semibold))
+                            .lineLimit(1)
+                        if context.state.isPlaying {
+                            LiveActivityMusicBars()
+                        }
+                    }
+                    .padding(.leading, 8)
+                }
+                DynamicIslandExpandedRegion(.center) {
+                    Text(context.state.artist)
+                        .font(.caption2)
+                        .foregroundStyle(.secondary)
+                        .lineLimit(1)
+                }
+                DynamicIslandExpandedRegion(.trailing) {
+                    Button(intent: SkipTrackIntent()) {
+                        HStack(spacing: 3) {
+                            Image(systemName: "forward.fill")
+                                .font(.system(size: 10, weight: .semibold))
+                            Text("Skip")
+                                .font(.caption2.weight(.medium))
+                        }
+                        .foregroundStyle(.white.opacity(0.6))
+                        .padding(.horizontal, 8)
+                        .padding(.vertical, 3)
+                        .background(.white.opacity(0.15))
+                        .clipShape(Capsule())
+                    }
+                    .buttonStyle(.plain)
+                    .padding(.trailing, 8)
+                }
+            } compactLeading: {
+                // ── Compact Leading ─────────────────────
+                Image(systemName: "music.note")
+                    .foregroundStyle(.green)
+                    .font(.system(size: 14))
+            } compactTrailing: {
+                // ── Compact Trailing ────────────────────
+                HStack(spacing: 3) {
+                    Image(systemName: "music.note")
+                        .font(.system(size: 10))
+                        .foregroundStyle(.green)
+                    Text(context.state.title)
+                        .font(.system(size: 10, weight: .medium))
+                        .lineLimit(1)
+                }
+            } minimal: {
+                // ── Minimal ─────────────────────────────
+                Image(systemName: "music.note")
+                    .foregroundStyle(.green)
+                    .font(.system(size: 13))
+            }
+            .widgetURL(URL(string: "tabatago://music")!)
+        }
+    }
+}
+
+// MARK: - LiveActivityMusicBars
+
+struct LiveActivityMusicBars: View {
+    var body: some View {
+        TimelineView(.periodic(from: .now, by: 0.45 / Double(barSpeeds.count))) { context in
+            HStack(spacing: 2) {
+                ForEach(0..<4, id: \.self) { i in
+                    let t = context.date.timeIntervalSinceReferenceDate
+                    let phase = t * barSpeeds[i] * 2 * .pi
+                    let h = barMin + (barMaxHeights[i] - barMin) * abs(sin(phase))
+                    Capsule()
+                        .fill(.green)
+                        .frame(width: 2, height: h)
+                }
+            }
+        }
+    }
+}
+
+private let barMaxHeights: [CGFloat] = [8, 14, 6, 12]
+private let barMin: CGFloat = 3
+private let barSpeeds: [Double] = [2.2, 1.8, 2.8, 1.5]