feat(ui): replace loading indicators with Apple-style LoadingSpinner

- Add LoadingSpinner component with small/medium/large sizes using system gray color
- Add LoadingPlaceholder for skeleton loading states
- Add LoadingSheet for full-screen blocking overlays
- Replace ThemedSpinner/ThemedSpinnerCompact across all views
- Remove deprecated loading components from AnimatedComponents.swift
- Delete LoadingTextGenerator.swift
- Fix PhotoImportView layout to fill full width

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

SportsTime/Features/Schedule/Views/ScheduleListView.swift

@@ -141,7 +141,7 @@ struct ScheduleListView: View {
 
     private var loadingView: some View {
         VStack(spacing: 16) {
-            ThemedSpinner(size: 44)
+            LoadingSpinner(size: .large)
             Text("Loading schedule...")
                 .foregroundStyle(.secondary)
         }