WorkoutKit Swift : sendInterval accepte blockSteps[] (N steps custom)

Avant : work + rest fixes (2 steps) avec repeats sur le couple.
Maintenant : payload optionnel blockSteps = [{type, duration_min, hr_zone},
...] qui permet N steps custom dans le bloc à répéter. Backward compat :
si pas de blockSteps, lit work + rest comme avant.

Refactor de sendCustomWorkout : prend stepsSpec: [(min, hrZone, isWork)]
au lieu de work*/rest* params séparés. Génère N IntervalSteps depuis le
spec, met dans 1 IntervalBlock avec iterations=repeats.

ios/App/App/CoachWorkoutKit.swift

@@ -60,13 +60,37 @@ public class CoachWorkoutKitPlugin: CAPPlugin, CAPBridgedPlugin {
         let cooldownMin = call.getDouble("cooldownMin") ?? 10
         let repeats = max(1, min(50, call.getInt("repeats") ?? 6))
 
+        // Nouveau format : blockSteps = [{ type, duration_min, hr_zone }, ...]
+        // type = "work" | "recovery"
+        // Backward compat : si pas blockSteps, lit work + rest comme avant.
+        var stepsSpec: [(min: Double, hrZone: Int?, isWork: Bool)] = []
+        if let raw = call.getArray("blockSteps") as? [[String: Any]], !raw.isEmpty {
+            for (i, s) in raw.enumerated() {
+                let durMin = (s["duration_min"] as? Double) ?? 0
+                if durMin <= 0 { continue }
+                let hrZone = s["hr_zone"] as? Int
+                let typeStr = (s["type"] as? String) ?? (i % 2 == 0 ? "work" : "recovery")
+                stepsSpec.append((durMin, hrZone, typeStr == "work"))
+            }
+        } else {
+            // Backward compat — work + rest (rest skipped si 0)
             let workDict = call.getObject("work") ?? [:]
             let workMin = workDict["duration_min"] as? Double ?? 3
             let workHrZone = workDict["hr_zone"] as? Int
+            stepsSpec.append((workMin, workHrZone, true))
 
             let restDict = call.getObject("rest") ?? [:]
             let restMin = restDict["duration_min"] as? Double ?? 1.5
             let restHrZone = restDict["hr_zone"] as? Int
+            if restMin > 0 {
+                stepsSpec.append((restMin, restHrZone, false))
+            }
+        }
+
+        if stepsSpec.isEmpty {
+            call.reject("Au moins 1 step (durée > 0) requis dans le bloc")
+            return
+        }
 
         let activity = workoutActivity(from: activityStr)
 
@@ -76,10 +100,7 @@ public class CoachWorkoutKitPlugin: CAPPlugin, CAPBridgedPlugin {
                     activity: activity,
                     displayName: displayName,
                     warmupMin: warmupMin,
-                    workMin: workMin,
-                    workHrZone: workHrZone,
-                    restMin: restMin,
-                    restHrZone: restHrZone,
+                    stepsSpec: stepsSpec,
                     repeats: repeats,
                     cooldownMin: cooldownMin
                 )
@@ -119,10 +140,7 @@ public class CoachWorkoutKitPlugin: CAPPlugin, CAPBridgedPlugin {
         activity: HKWorkoutActivityType,
         displayName: String,
         warmupMin: Double,
-        workMin: Double,
-        workHrZone: Int?,
-        restMin: Double,
-        restHrZone: Int?,
+        stepsSpec: [(min: Double, hrZone: Int?, isWork: Bool)],
         repeats: Int,
         cooldownMin: Double
     ) async throws {
@@ -130,24 +148,21 @@ public class CoachWorkoutKitPlugin: CAPPlugin, CAPBridgedPlugin {
         // 1. Warmup — un WorkoutStep avec un goal time
         let warmupStep = WorkoutStep(goal: .time(warmupMin * 60, .seconds))
 
-        // 2. Work step — wrapped dans un IntervalStep avec purpose .work
-        var workWorkoutStep = WorkoutStep(goal: .time(workMin * 60, .seconds))
-        if let zone = workHrZone {
-            workWorkoutStep.alert = HeartRateZoneAlert(zone: zone)
+        // 2. Construit la liste d'IntervalSteps depuis stepsSpec.
+        //    Chaque entrée = (durée min, zone HR optionnelle, isWork bool).
+        let intervalSteps: [IntervalStep] = stepsSpec.map { spec in
+            var ws = WorkoutStep(goal: .time(spec.min * 60, .seconds))
+            if let zone = spec.hrZone {
+                ws.alert = HeartRateZoneAlert(zone: zone)
             }
-        let workInterval = IntervalStep(.work, step: workWorkoutStep)
-
-        // 3. Rest step — IntervalStep purpose .recovery
-        var restWorkoutStep = WorkoutStep(goal: .time(restMin * 60, .seconds))
-        if let zone = restHrZone {
-            restWorkoutStep.alert = HeartRateZoneAlert(zone: zone)
+            return IntervalStep(spec.isWork ? .work : .recovery, step: ws)
         }
-        let restInterval = IntervalStep(.recovery, step: restWorkoutStep)
 
-        // 4. Block répété N fois
-        let block = IntervalBlock(steps: [workInterval, restInterval], iterations: repeats)
+        // 3. Block répété N fois — la séquence COMPLÈTE de tous les steps
+        //    se répète repeats fois.
+        let block = IntervalBlock(steps: intervalSteps, iterations: repeats)
 
-        // 5. Cooldown
+        // 4. Cooldown
         let cooldownStep = WorkoutStep(goal: .time(cooldownMin * 60, .seconds))
 
         // 6. CustomWorkout — location selon l'activité (indoor pour