feat(watch): add workout summary screen with HealthKit data

targets/watch/Views/ActiveWorkoutView.swift

@@ -61,7 +61,7 @@ struct SwimView: View {
                     Image(systemName: "flame.fill")
                         .foregroundColor(.orange)
                         .font(.caption)
-                    Text("\(Int(workoutManager.estimatedCalories))")
+                    Text("\(Int(workoutManager.activeCalories))")
                         .font(.caption)
                 }
 
@@ -143,7 +143,7 @@ struct RestView: View {
                     Image(systemName: "flame.fill")
                         .font(.caption)
                         .foregroundColor(.orange)
-                    Text("\(Int(workoutManager.estimatedCalories))kcal")
+                    Text("\(Int(workoutManager.activeCalories))kcal")
                         .font(.caption)
                 }
             }

targets/watch/Views/WorkoutSummaryView.swift

@@ -0,0 +1,81 @@
+import SwiftUI
+
+struct WorkoutSummaryView: View {
+    @ObservedObject var workoutManager: WorkoutManager
+
+    var body: some View {
+        if let summary = workoutManager.workoutSummary {
+            List {
+                Section {
+                    VStack(spacing: 8) {
+                        Image(systemName: "checkmark.circle.fill")
+                            .font(.system(size: 40))
+                            .foregroundColor(.green)
+
+                        Text("Workout complete!")
+                            .font(.headline)
+                            .foregroundColor(.green)
+                    }
+                    .frame(maxWidth: .infinity)
+                    .padding(.vertical, 8)
+                }
+
+                Section("Stats") {
+                    HStack {
+                        Text("Total time")
+                            .foregroundColor(.secondary)
+                        Spacer()
+                        Text(formatTime(summary.duration))
+                            .monospacedDigit()
+                    }
+
+                    HStack {
+                        Text("Distance")
+                            .foregroundColor(.secondary)
+                        Spacer()
+                        Text("\(summary.totalDistance)m")
+                            .monospacedDigit()
+                    }
+
+                    HStack {
+                        Text("Calories")
+                            .foregroundColor(.secondary)
+                        Spacer()
+                        Text("\(summary.calories)kcal")
+                            .monospacedDigit()
+                    }
+
+                    HStack {
+                        Text("Laps")
+                            .foregroundColor(.secondary)
+                        Spacer()
+                        Text("\(summary.laps.count)")
+                            .monospacedDigit()
+                    }
+                }
+
+                Section {
+                    Button {
+                        workoutManager.dismissSummary()
+                    } label: {
+                        HStack {
+                            Spacer()
+                            Text("OK")
+                                .font(.headline)
+                            Spacer()
+                        }
+                    }
+                    .buttonStyle(.borderedProminent)
+                    .tint(.cyan)
+                }
+            }
+            .listStyle(.automatic)
+        }
+    }
+
+    private func formatTime(_ seconds: TimeInterval) -> String {
+        let mins = Int(seconds) / 60
+        let secs = Int(seconds) % 60
+        return String(format: "%d:%02d", mins, secs)
+    }
+}