feat(live-native): cardiac-aware zones temps réel dans CoachLiveView

CoachLiveBridge.openNativeLive lit maintenant le token JS et le passe à
CoachLiveView(authToken:). La vue fetch /api/cardiac-zones au .onAppear
+ stocke en @State.

CardiacZones struct (Decodable) calque la payload du backend :
- méthode (karvonen / fcmax_pct), beta-bloquant, fcmax/fcrest observées, HRR
- Z1-Z5 lo/hi + clinical_target_bpm (HRKarv0.6 sous bb, Díaz-Buschmann 2014)
- zoneFor(hr:) -> ZoneMatch {id, lo, hi, color}

HRMetricCard (variante de MetricCard pour FC) :
- Chiffre + glow change de couleur dynamiquement selon zone courante
  (cyan Z1 récup -> rouge Z5 VO2max). Animation .easeOut 0.25s.
- Pill "Z3 · 128-145" sous l'unité bpm.
- "✓ Utile" si beta-bloqué + HR ≥ clinical_target_bpm.

Méthode 100% alignée Apple Watch Workout app (Karvonen HRR, recalc mensuel
max/rest, 5 zones) + ACSM. Aucune extrapolation.

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

ios/App/App/CoachLiveBridge.swift

@@ -70,17 +70,19 @@ public class CoachLiveBridgePlugin: CAPPlugin, CAPBridgedPlugin {
             call.resolve(["presented": false, "reason": "iOS < 26"])
             return
         }
+        // Token passé par le JS pour que CoachLiveView puisse fetch
+        // /api/cardiac-zones (auth backend = token query param accepté).
+        let token = call.getString("token") ?? ""
         DispatchQueue.main.async { [weak self] in
             guard let vc = self?.bridge?.viewController else {
                 call.resolve(["presented": false, "reason": "no host vc"])
                 return
             }
-            // Évite de re-présenter si une autre vue est déjà au-dessus.
             if vc.presentedViewController != nil {
                 call.resolve(["presented": false, "reason": "already presented"])
                 return
             }
-            let host = UIHostingController(rootView: CoachLiveView())
+            let host = UIHostingController(rootView: CoachLiveView(authToken: token))
             host.modalPresentationStyle = .fullScreen
             host.view.backgroundColor = .black
             vc.present(host, animated: true) {

ios/App/App/CoachLiveView.swift

@@ -9,11 +9,57 @@
 
 import SwiftUI
 
+// ─── Cardiac-aware zones (Karvonen HRR si beta-bloquant, %FCmax sinon).
+// Méthode alignée Apple Watch Workout app (apd897dccddf) + ACSM Guidelines.
+// Fetché depuis /api/cardiac-zones au .onAppear de CoachLiveView.
+struct CardiacZones: Decodable {
+    let method: String
+    let hasBetablocker: Bool
+    let fcmaxUsed: Int
+    let fcrestUsed: Int?
+    let hrr: Int?
+    let clinicalTargetBpm: Int?
+    let z1: [Int]
+    let z2: [Int]
+    let z3: [Int]
+    let z4: [Int]
+    let z5: [Int]
+
+    enum CodingKeys: String, CodingKey {
+        case method
+        case hasBetablocker = "has_betablocker"
+        case fcmaxUsed = "fcmax_used"
+        case fcrestUsed = "fcrest_used"
+        case hrr
+        case clinicalTargetBpm = "clinical_target_bpm"
+        case z1 = "Z1", z2 = "Z2", z3 = "Z3", z4 = "Z4", z5 = "Z5"
+    }
+
+    struct ZoneMatch { let id: String; let lo: Int; let hi: Int; let color: Color }
+
+    func zoneFor(hr: Int) -> ZoneMatch? {
+        guard hr > 0 else { return nil }
+        // Cherche Z5 → Z1 (le premier match en descendant).
+        let table: [(String, [Int], Color)] = [
+            ("Z5", z5, .red), ("Z4", z4, .orange),
+            ("Z3", z3, .yellow), ("Z2", z2, .green), ("Z1", z1, .cyan),
+        ]
+        for (id, range, color) in table where range.count == 2 && hr >= range[0] {
+            return ZoneMatch(id: id, lo: range[0], hi: range[1], color: color)
+        }
+        return nil
+    }
+}
+
 @available(iOS 26.0, *)
 struct CoachLiveView: View {
+    let authToken: String
     @StateObject private var store = LiveStore.shared
     @Environment(\.dismiss) private var dismiss
     @State private var pulse: Bool = false
+    @State private var zones: CardiacZones?
+
+    init(authToken: String = "") { self.authToken = authToken }
 
     var body: some View {
         ZStack {
@@ -27,10 +73,10 @@ struct CoachLiveView: View {
                     LazyVGrid(columns: [GridItem(.flexible(), spacing: 14),
                                         GridItem(.flexible(), spacing: 14)],
                               spacing: 14) {
-                        MetricCard(label: "Fréquence",
-                                   value: store.heartRateText,
-                                   unit: "bpm",
-                                   color: .red,
+                        // HR card : couleur dynamique selon zone cardio courante.
+                        HRMetricCard(value: store.heartRateText,
+                                     hrInt: Int(store.heartRate),
+                                     zones: zones,
                                      isPulsing: store.status == .live,
                                      pulsePhase: pulse)
                         MetricCard(label: "Calories",
@@ -76,6 +122,27 @@ struct CoachLiveView: View {
             withAnimation(.easeInOut(duration: 0.55).repeatForever(autoreverses: true)) {
                 pulse = true
             }
+            fetchZones()
+        }
+    }
+
+    // ─── Fetch /api/cardiac-zones (token query param requis pour _check_auth)
+    private func fetchZones() {
+        guard zones == nil else { return }
+        var comps = URLComponents(string: "https://coach.hypnotruck.ch/api/cardiac-zones")
+        if !authToken.isEmpty {
+            comps?.queryItems = [URLQueryItem(name: "token", value: authToken)]
+        }
+        guard let url = comps?.url else { return }
+        Task {
+            do {
+                let (data, resp) = try await URLSession.shared.data(from: url)
+                guard let http = resp as? HTTPURLResponse, http.statusCode == 200 else { return }
+                let parsed = try JSONDecoder().decode(CardiacZones.self, from: data)
+                await MainActor.run { self.zones = parsed }
+            } catch {
+                // Silencieux : si fetch échoue, la HR card retombe sur couleur rouge fixe (fallback OK).
+            }
         }
     }
 
@@ -177,3 +244,64 @@ private struct MetricCard: View {
         .scaleEffect(isPulsing && pulsePhase ? 1.025 : 1.0)
     }
 }
+
+// ─── HRMetricCard : variante spécialisée FC avec zone cardio dynamique
+// (couleur + pill Z1-Z5 + indicateur "zone utile" si beta-bloquant et
+// HR ≥ clinical_target_bpm = HRKarv0.6 per Díaz-Buschmann 2014 ESC).
+
+@available(iOS 26.0, *)
+private struct HRMetricCard: View {
+    let value: String
+    let hrInt: Int
+    let zones: CardiacZones?
+    let isPulsing: Bool
+    let pulsePhase: Bool
+
+    private var match: CardiacZones.ZoneMatch? { zones?.zoneFor(hr: hrInt) }
+    private var color: Color { match?.color ?? .red }
+    private var isUsefulZone: Bool {
+        guard let target = zones?.clinicalTargetBpm else { return false }
+        return hrInt >= target
+    }
+
+    var body: some View {
+        VStack(spacing: 6) {
+            Text("FRÉQUENCE")
+                .font(.caption2.weight(.semibold))
+                .foregroundStyle(.secondary)
+                .tracking(0.6)
+            Text(value)
+                .font(.system(size: 48, weight: .heavy, design: .rounded).monospacedDigit())
+                .foregroundStyle(color)
+                .shadow(color: color.opacity(0.55), radius: 18, x: 0, y: 0)
+                .contentTransition(.numericText())
+                .animation(.easeOut(duration: 0.25), value: color)
+            Text("bpm")
+                .font(.caption2)
+                .foregroundStyle(.tertiary)
+            if let m = match {
+                HStack(spacing: 6) {
+                    Text("\(m.id) · \(m.lo)-\(m.hi)")
+                        .font(.caption2.weight(.bold))
+                        .tracking(0.5)
+                        .foregroundStyle(m.color)
+                        .padding(.horizontal, 8).padding(.vertical, 3)
+                        .background(m.color.opacity(0.22),
+                                    in: Capsule())
+                    if isUsefulZone {
+                        Text("✓ Utile")
+                            .font(.caption2.weight(.bold))
+                            .foregroundStyle(.green)
+                    }
+                }
+                .padding(.top, 2)
+            }
+        }
+        .frame(maxWidth: .infinity, minHeight: 130)
+        .padding(.vertical, 14)
+        .glassEffect(.regular.tint(color.opacity(0.18)),
+                     in: RoundedRectangle(cornerRadius: 22, style: .continuous))
+        .scaleEffect(isPulsing && pulsePhase ? 1.025 : 1.0)
+        .animation(.easeOut(duration: 0.25), value: color)
+    }
+}