Add Stadium Progress system and themed loading spinners

Stadium Progress & Achievements:
- Add StadiumVisit and Achievement SwiftData models
- Create Progress tab with interactive map view
- Implement photo-based visit import with GPS/date matching
- Add achievement badges (count-based, regional, journey)
- Create shareable progress cards for social media
- Add canonical data infrastructure (stadium identities, team aliases)
- Implement score resolution from free APIs (MLB, NBA, NHL stats)

UI Improvements:
- Add ThemedSpinner and ThemedSpinnerCompact components
- Replace all ProgressView() with themed spinners throughout app
- Fix sport selection state not persisting when navigating away

Bug Fixes:
- Fix Coast to Coast trips showing only 1 city (validation issue)
- Fix stadium progress showing 0/0 (filtering issue)
- Remove "Stadium Quest" title from progress view

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

SportsTime/Features/Schedule/Views/ScheduleListView.swift

@@ -6,6 +6,7 @@
 import SwiftUI
 
 struct ScheduleListView: View {
+    @Environment(\.colorScheme) private var colorScheme
     @State private var viewModel = ScheduleViewModel()
     @State private var showDatePicker = false
 
@@ -97,9 +98,11 @@ struct ScheduleListView: View {
                     Text(formatSectionDate(dateGroup.date))
                         .font(.headline)
                 }
+                .listRowBackground(Theme.cardBackground(colorScheme))
             }
         }
         .listStyle(.plain)
+        .scrollContentBackground(.hidden)
         .refreshable {
             await viewModel.loadGames()
         }
@@ -128,8 +131,7 @@ struct ScheduleListView: View {
 
     private var loadingView: some View {
         VStack(spacing: 16) {
-            ProgressView()
-                .scaleEffect(1.5)
+            ThemedSpinner(size: 44)
             Text("Loading schedule...")
                 .foregroundStyle(.secondary)
         }