refactor: change domain model IDs from UUID to String canonical IDs

This refactor fixes the achievement system by using stable canonical string
IDs (e.g., "stadium_mlb_fenway_park") instead of random UUIDs. This ensures
stadium mappings for achievements are consistent across app launches and
CloudKit sync operations.

Changes:
- Stadium, Team, Game: id property changed from UUID to String
- Trip, TripStop, TripPreferences: updated to use String IDs for games/stadiums
- CKModels: removed UUID parsing, use canonical IDs directly
- AchievementEngine: now matches against canonical stadium IDs
- All test files updated to use String IDs instead of UUID()

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

SportsTime/Export/Services/PDFAssetPrefetcher.swift

@@ -15,8 +15,8 @@ actor PDFAssetPrefetcher {
     struct PrefetchedAssets {
         let routeMap: UIImage?
         let cityMaps: [String: UIImage]
-        let teamLogos: [UUID: UIImage]
-        let stadiumPhotos: [UUID: UIImage]
+        let teamLogos: [String: UIImage]
+        let stadiumPhotos: [String: UIImage]
         let cityPOIs: [String: [POISearchService.POI]]
 
         var isEmpty: Bool {
@@ -63,7 +63,7 @@ actor PDFAssetPrefetcher {
     /// - Returns: All prefetched assets
     func prefetchAssets(
         for trip: Trip,
-        games: [UUID: RichGame],
+        games: [String: RichGame],
         progressCallback: ((PrefetchProgress) async -> Void)? = nil
     ) async -> PrefetchedAssets {
         var progress = PrefetchProgress()
@@ -71,8 +71,8 @@ actor PDFAssetPrefetcher {
         // Collect unique teams and stadiums from games
         var teams: [Team] = []
         var stadiums: [Stadium] = []
-        var seenTeamIds: Set<UUID> = []
-        var seenStadiumIds: Set<UUID> = []
+        var seenTeamIds: Set<String> = []
+        var seenStadiumIds: Set<String> = []
 
         for (_, richGame) in games {
             if !seenTeamIds.contains(richGame.homeTeam.id) {

SportsTime/Export/Services/RemoteImageService.swift

@@ -111,8 +111,8 @@ actor RemoteImageService {
     }
 
     /// Fetch team logos by team ID
-    func fetchTeamLogos(teams: [Team]) async -> [UUID: UIImage] {
-        let urlToTeam: [URL: UUID] = Dictionary(
+    func fetchTeamLogos(teams: [Team]) async -> [String: UIImage] {
+        let urlToTeam: [URL: String] = Dictionary(
             uniqueKeysWithValues: teams.compactMap { team in
                 guard let logoURL = team.logoURL else { return nil }
                 return (logoURL, team.id)
@@ -121,7 +121,7 @@ actor RemoteImageService {
 
         let images = await fetchImages(from: Array(urlToTeam.keys))
 
-        var result: [UUID: UIImage] = [:]
+        var result: [String: UIImage] = [:]
         for (url, image) in images {
             if let teamId = urlToTeam[url] {
                 result[teamId] = image
@@ -132,8 +132,8 @@ actor RemoteImageService {
     }
 
     /// Fetch stadium photos by stadium ID
-    func fetchStadiumPhotos(stadiums: [Stadium]) async -> [UUID: UIImage] {
-        let urlToStadium: [URL: UUID] = Dictionary(
+    func fetchStadiumPhotos(stadiums: [Stadium]) async -> [String: UIImage] {
+        let urlToStadium: [URL: String] = Dictionary(
             uniqueKeysWithValues: stadiums.compactMap { stadium in
                 guard let imageURL = stadium.imageURL else { return nil }
                 return (imageURL, stadium.id)
@@ -142,7 +142,7 @@ actor RemoteImageService {
 
         let images = await fetchImages(from: Array(urlToStadium.keys))
 
-        var result: [UUID: UIImage] = [:]
+        var result: [String: UIImage] = [:]
         for (url, image) in images {
             if let stadiumId = urlToStadium[url] {
                 result[stadiumId] = image