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/CelebrationAnimations.swift

@@ -106,7 +106,8 @@ struct CelebrationOverlayView: View {
         .frame(maxWidth: .infinity, maxHeight: .infinity)
         .onAppear {
             hasAppeared = true
-            DispatchQueue.main.asyncAfter(deadline: .now() + animationType.duration) {
+            Task { @MainActor in
+                try? await Task.sleep(for: .seconds(animationType.duration))
                 onComplete()
             }
         }
@@ -341,7 +342,8 @@ struct ShatterReformAnimation: View {
             }
 
             // Phase 2: Converge to center and fade
-            DispatchQueue.main.asyncAfter(deadline: .now() + 0.6) {
+            Task { @MainActor in
+                try? await Task.sleep(for: .seconds(0.6))
                 phase = .reform
                 withAnimation(.easeInOut(duration: 0.5)) {
                     for i in 0..<shardCount {
@@ -353,14 +355,16 @@ struct ShatterReformAnimation: View {
             }
 
             // Phase 3: Show checkmark
-            DispatchQueue.main.asyncAfter(deadline: .now() + 1.1) {
+            Task { @MainActor in
+                try? await Task.sleep(for: .seconds(1.1))
                 withAnimation(.spring(response: 0.3, dampingFraction: 0.6)) {
                     checkmarkOpacity = 1
                 }
             }
 
             // Phase 4: Fade out
-            DispatchQueue.main.asyncAfter(deadline: .now() + 1.8) {
+            Task { @MainActor in
+                try? await Task.sleep(for: .seconds(1.8))
                 withAnimation(.easeOut(duration: 0.3)) {
                     checkmarkOpacity = 0
                 }