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/Planning/Engine/ScenarioCPlanner.swift

@@ -272,7 +272,7 @@ final class ScenarioCPlanner: ScenarioPlanner {
     /// Finds all stadiums in a given city (case-insensitive match).
     private func findStadiumsInCity(
         cityName: String,
-        stadiums: [UUID: Stadium]
+        stadiums: [String: Stadium]
     ) -> [Stadium] {
         let normalizedCity = cityName.lowercased().trimmingCharacters(in: .whitespaces)
         return stadiums.values.filter { stadium in
@@ -296,14 +296,14 @@ final class ScenarioCPlanner: ScenarioPlanner {
     private func findDirectionalStadiums(
         from start: CLLocationCoordinate2D,
         to end: CLLocationCoordinate2D,
-        stadiums: [UUID: Stadium]
-    ) -> Set<UUID> {
+        stadiums: [String: Stadium]
+    ) -> Set<String> {
         let directDistance = distanceBetween(start, end)
 
         // Allow detours up to 50% longer than direct distance
         let maxDetourDistance = directDistance * 1.5
 
-        var directionalIds: Set<UUID> = []
+        var directionalIds: Set<String> = []
 
         for (id, stadium) in stadiums {
             let stadiumCoord = stadium.coordinate
@@ -349,8 +349,8 @@ final class ScenarioCPlanner: ScenarioPlanner {
     ///     Create a date range from start_game.date to end_game.date
     ///
     private func generateDateRanges(
-        startStadiumIds: Set<UUID>,
-        endStadiumIds: Set<UUID>,
+        startStadiumIds: Set<String>,
+        endStadiumIds: Set<String>,
         allGames: [Game],
         request: PlanningRequest
     ) -> [DateInterval] {
@@ -417,7 +417,7 @@ final class ScenarioCPlanner: ScenarioPlanner {
     /// Creates separate stops when visiting the same city with other cities in between.
     private func buildStops(
         from games: [Game],
-        stadiums: [UUID: Stadium]
+        stadiums: [String: Stadium]
     ) -> [ItineraryStop] {
         guard !games.isEmpty else { return [] }
 
@@ -426,7 +426,7 @@ final class ScenarioCPlanner: ScenarioPlanner {
 
         // Group consecutive games at the same stadium
         var stops: [ItineraryStop] = []
-        var currentStadiumId: UUID? = nil
+        var currentStadiumId: String? = nil
         var currentGames: [Game] = []
 
         for game in sortedGames {
@@ -458,8 +458,8 @@ final class ScenarioCPlanner: ScenarioPlanner {
     /// Creates an ItineraryStop from a group of games at the same stadium.
     private func createStop(
         from games: [Game],
-        stadiumId: UUID,
-        stadiums: [UUID: Stadium]
+        stadiumId: String,
+        stadiums: [String: Stadium]
     ) -> ItineraryStop? {
         guard !games.isEmpty else { return nil }
 
@@ -496,7 +496,7 @@ final class ScenarioCPlanner: ScenarioPlanner {
         start: LocationInput,
         end: LocationInput,
         games: [Game],
-        stadiums: [UUID: Stadium]
+        stadiums: [String: Stadium]
     ) -> [ItineraryStop] {
 
         var stops: [ItineraryStop] = []