Fix 8 audit items: remove force-unwraps, improve accessibility and concurrency

- Replace force-unwrap HK types with modern HKQuantityType(_:) initializer
- Replace Calendar.date force-unwraps with guard/let in HealthService, HeaderPercView, MoodStreakActivity, DayViewViewModel, MonthTotalTemplate
- Extract DayViewViewModel.countEntries into testable static method with safe flatMap
- Replace DispatchQueue.main.asyncAfter with Task.sleep in CelebrationAnimations
- Add .minimumScaleFactor(0.5) to SmallRollUpHeaderView for Dynamic Type
- Add VoiceOver accessibility labels to HeaderPercView mood percentages
- Fix @testable import iFeel → Feels in Tests_iOS.swift
- Add 4 unit tests for countEntries (TDD)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Shared/Views/SharingTemplates/MonthTotalTemplate.swift

@@ -17,7 +17,7 @@ struct MonthTotalTemplate: View, SharingTemplate {
     var endDate: Date
     var totalEntryCount: Int = 0
     
-    private var month = Calendar.current.dateComponents([.month], from: Date()).month!
+    private var month = Calendar.current.dateComponents([.month], from: Date()).month ?? 1
     
     @State var showSharingTemplate = false
     @StateObject private var shareImage = ShareImageStateViewModel()