feat(watch): complications Apple Watch (Forme + Séance du jour)

L'App Group n'étant pas partagé entre appareils, le snapshot transite par
WatchConnectivity : iPhone CoachWidgetBridge.pushToWatch (updateApplicationContext)
-> CoachWatch/ConnectivityManager reçoit -> App Group de la montre + reload des
complications. Nouvelles complications (CoachWatchWidgets/CoachWatchComplications.swift) :
Forme (accessoryCircular/corner, Gauge) + Séance du jour (accessoryRectangular/inline).

⚠️ Reste Mac : créer la target widget watchOS + App Group/capability + Target
Membership. Runbook complet dans docs/widgets-runbook-mac.md.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ios/App/CoachWatch/ConnectivityManager.swift

@@ -1,5 +1,6 @@
 import Foundation
 import WatchConnectivity
+import WidgetKit
 import os
 
 private let connLog = Logger(subsystem: "ch.hypnotruck.coach.watchkitapp", category: "connectivity")
@@ -78,4 +79,26 @@ extension ConnectivityManager: WCSessionDelegate {
             queue.async { [weak self] in self?.flushLocked() }
         }
     }
+
+    // ─── Réception du snapshot widget (iPhone → Watch) ───
+    // L'iPhone (CoachWidgetBridge) pousse les données du jour ; on les persiste
+    // dans l'App Group de CETTE montre et on recharge les complications.
+
+    func session(_ session: WCSession, didReceiveApplicationContext applicationContext: [String: Any]) {
+        storeWidgetSnapshot(applicationContext)
+    }
+
+    func session(_ session: WCSession, didReceiveUserInfo userInfo: [String: Any] = [:]) {
+        storeWidgetSnapshot(userInfo)
+    }
+
+    private func storeWidgetSnapshot(_ dict: [String: Any]) {
+        guard let data = dict["widgetSnapshot"] as? Data,
+              let snapshot = try? JSONDecoder().decode(CoachWidgetSnapshot.self, from: data) else { return }
+        CoachWidgetStore.save(snapshot)
+        connLog.info("widgetSnapshot reçu de l'iPhone -> complications rechargées")
+        DispatchQueue.main.async {
+            WidgetCenter.shared.reloadAllTimelines()
+        }
+    }
 }