feat: Initial iOS Health Dashboard app (Swift + SwiftUI)

PulseHealth/Services/HealthKitService.swift

@@ -0,0 +1,32 @@
+import HealthKit
+
+class HealthKitService: ObservableObject {
+    let healthStore = HKHealthStore()
+    var isAvailable: Bool { HKHealthStore.isHealthDataAvailable() }
+
+    func requestAuthorization() async throws {
+        let typesToRead: Set<HKObjectType> = [
+            HKQuantityType(.heartRate),
+            HKQuantityType(.restingHeartRate),
+            HKQuantityType(.heartRateVariabilitySDNN),
+            HKQuantityType(.stepCount),
+            HKQuantityType(.activeEnergyBurned),
+            HKQuantityType(.oxygenSaturation),
+            HKCategoryType(.sleepAnalysis),
+        ]
+        try await healthStore.requestAuthorization(toShare: [], read: typesToRead)
+    }
+
+    func fetchTodaySteps() async -> Int {
+        guard let type = HKQuantityType.quantityType(forIdentifier: .stepCount) else { return 0 }
+        let now = Date()
+        let startOfDay = Calendar.current.startOfDay(for: now)
+        let predicate = HKQuery.predicateForSamples(withStart: startOfDay, end: now)
+        return await withCheckedContinuation { cont in
+            let q = HKStatisticsQuery(quantityType: type, quantitySamplePredicate: predicate, options: .cumulativeSum) { _, result, _ in
+                cont.resume(returning: Int(result?.sumQuantity()?.doubleValue(for: .count()) ?? 0))
+            }
+            healthStore.execute(q)
+        }
+    }
+}