feat(watchos): UI live workout + entry point (Phase 2)

CoachWatchApp: WKApplicationDelegateAdaptor active WCSession au boot, injecte les
managers. ContentView: picker 4 activités (course/vélo/marche/renfo) -> vue live
(FC/calories/distance/durée + état liaison iPhone) -> bouton Terminer. Build OK.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ios/App/CoachWatch/CoachWatchApp.swift

@@ -1,10 +1,22 @@
 import SwiftUI
+import WatchKit
 
 @main
 struct CoachWatchApp: App {
+    @WKApplicationDelegateAdaptor private var appDelegate: WatchAppDelegate
+
     var body: some Scene {
         WindowGroup {
             ContentView()
+                .environmentObject(WorkoutManager.shared)
+                .environmentObject(ConnectivityManager.shared)
         }
     }
 }
+
+final class WatchAppDelegate: NSObject, WKApplicationDelegate {
+    func applicationDidFinishLaunching() {
+        // Active WCSession dès le boot pour ne rater aucun early message.
+        _ = ConnectivityManager.shared
+    }
+}

ios/App/CoachWatch/ContentView.swift

@@ -1,20 +1,134 @@
 import SwiftUI
+import HealthKit
 
 struct ContentView: View {
+    @EnvironmentObject private var workout: WorkoutManager
+
     var body: some View {
+        if workout.isRunning {
+            LiveWorkoutView()
+        } else {
+            ActivityPickerView()
+        }
+    }
+}
+
+struct ActivityPickerView: View {
+    @EnvironmentObject private var workout: WorkoutManager
+
+    private struct Activity: Identifiable {
+        let id = UUID()
+        let label: String
+        let symbol: String
+        let type: HKWorkoutActivityType
+        let location: HKWorkoutSessionLocationType
+    }
+
+    private let activities: [Activity] = [
+        .init(label: "Course", symbol: "figure.run", type: .running, location: .outdoor),
+        .init(label: "Vélo", symbol: "figure.outdoor.cycle", type: .cycling, location: .outdoor),
+        .init(label: "Marche", symbol: "figure.walk", type: .walking, location: .outdoor),
+        .init(label: "Renfo", symbol: "dumbbell", type: .traditionalStrengthTraining, location: .indoor)
+    ]
+
+    var body: some View {
+        ScrollView {
             VStack(spacing: 8) {
-            Image(systemName: "heart.fill")
+                ForEach(activities) { activity in
+                    Button {
+                        Task {
+                            await workout.startWorkout(activityType: activity.type,
+                                                       locationType: activity.location)
+                        }
+                    } label: {
+                        Label(activity.label, systemImage: activity.symbol)
+                            .frame(maxWidth: .infinity, alignment: .leading)
+                    }
+                }
+                if let message = workout.statusMessage {
+                    Text(message)
+                        .font(.footnote)
                         .foregroundStyle(.red)
-            Text("Coach")
-                .font(.headline)
-            Text("Prêt")
+                }
+            }
+            .padding(.horizontal, 4)
+        }
+        .navigationTitle("Coach")
+    }
+}
+
+struct LiveWorkoutView: View {
+    @EnvironmentObject private var workout: WorkoutManager
+    @EnvironmentObject private var connectivity: ConnectivityManager
+
+    var body: some View {
+        ScrollView {
+            VStack(alignment: .leading, spacing: 10) {
+                Metric(label: "FC", value: "\(Int(workout.heartRate))", unit: "bpm", color: .red)
+                Metric(label: "Calories", value: "\(Int(workout.activeEnergyKcal))", unit: "kcal", color: .orange)
+                Metric(label: "Distance",
+                       value: String(format: "%.2f", workout.distanceMeters / 1000),
+                       unit: "km", color: .blue)
+                Metric(label: "Durée", value: Self.timeString(workout.elapsedSec), unit: "", color: .green)
+
+                HStack(spacing: 4) {
+                    Image(systemName: connectivity.isReachable
+                          ? "iphone.radiowaves.left.and.right" : "iphone.slash")
+                        .foregroundStyle(connectivity.isReachable ? .green : .secondary)
+                    Text(connectivity.isReachable ? "iPhone connecté" : "iPhone hors de portée")
+                        .font(.caption2)
+                        .foregroundStyle(.secondary)
+                }
+
+                Button(role: .destructive) {
+                    workout.end()
+                } label: {
+                    Label("Terminer", systemImage: "stop.fill")
+                        .frame(maxWidth: .infinity)
+                }
+            }
+            .padding(.horizontal, 4)
+        }
+    }
+
+    private static func timeString(_ seconds: Double) -> String {
+        let total = Int(seconds)
+        let h = total / 3600
+        let m = (total % 3600) / 60
+        let s = total % 60
+        return h > 0
+            ? String(format: "%d:%02d:%02d", h, m, s)
+            : String(format: "%02d:%02d", m, s)
+    }
+}
+
+private struct Metric: View {
+    let label: String
+    let value: String
+    let unit: String
+    let color: Color
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 0) {
+            Text(label)
+                .font(.caption2)
+                .foregroundStyle(.secondary)
+            HStack(alignment: .firstTextBaseline, spacing: 2) {
+                Text(value)
+                    .font(.system(size: 30, weight: .semibold, design: .rounded))
+                    .foregroundStyle(color)
+                if !unit.isEmpty {
+                    Text(unit)
                         .font(.caption)
                         .foregroundStyle(.secondary)
                 }
-        .padding()
+            }
+        }
     }
 }
 
 #Preview {
     ContentView()
+        .environmentObject(WorkoutManager.shared)
+        .environmentObject(ConnectivityManager.shared)
 }