b4813272f6
Completes 'available HealthKit trends' for weekly/monthly reports. Adds HealthKitManager.dailyReference (3 parallel bucketed HKStatisticsCollectionQuery for steps/active-calories/resting-HR over ~13 months), AnalyticsService. refreshHealthReference to cache and merge it into DaySamples, and avgSteps/ avgActiveCalories/avgRestingHR on PeriodSummary (nil when absent — honest). Surfaced in AnalyticsView's weekly/monthly cards. Verified standalone (swiftc, 8/8): aggregation correct when present, nil when absent, workout metrics unaffected, reports stay deterministic. Tests added to AnalyticsEngineTests. This completes all analytics logic — remaining work is the first Xcode build (device, user-run) to catch any SwiftUI compile issues. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>