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/Core/Models/Local/CanonicalModels.swift

@@ -163,7 +163,7 @@ final class CanonicalStadium {
 
     func toDomain() -> Stadium {
         Stadium(
-            id: uuid,
+            id: canonicalId,
             name: name,
             city: city,
             state: state,
@@ -299,14 +299,14 @@ final class CanonicalTeam {
 
     var sportEnum: Sport? { Sport(rawValue: sport) }
 
-    func toDomain(stadiumUUID: UUID) -> Team {
+    func toDomain() -> Team {
         Team(
-            id: uuid,
+            id: canonicalId,
             name: name,
             abbreviation: abbreviation,
             sport: sportEnum ?? .mlb,
             city: city,
-            stadiumId: stadiumUUID,
+            stadiumId: stadiumCanonicalId,
             logoURL: logoURL.flatMap { URL(string: $0) },
             primaryColor: primaryColor,
             secondaryColor: secondaryColor
@@ -466,12 +466,12 @@ final class CanonicalGame {
 
     var sportEnum: Sport? { Sport(rawValue: sport) }
 
-    func toDomain(homeTeamUUID: UUID, awayTeamUUID: UUID, stadiumUUID: UUID) -> Game {
+    func toDomain() -> Game {
         Game(
-            id: uuid,
-            homeTeamId: homeTeamUUID,
-            awayTeamId: awayTeamUUID,
-            stadiumId: stadiumUUID,
+            id: canonicalId,
+            homeTeamId: homeTeamCanonicalId,
+            awayTeamId: awayTeamCanonicalId,
+            stadiumId: stadiumCanonicalId,
             dateTime: dateTime,
             sport: sportEnum ?? .mlb,
             season: season,

SportsTime/Core/Models/Local/SavedTrip.swift

@@ -16,7 +16,7 @@ final class SavedTrip {
     var updatedAt: Date
     var status: String
     var tripData: Data  // Encoded Trip struct
-    var gamesData: Data?  // Encoded [UUID: RichGame] dictionary
+    var gamesData: Data?  // Encoded [String: RichGame] dictionary
 
     @Relationship(deleteRule: .cascade)
     var votes: [TripVote]?
@@ -43,16 +43,16 @@ final class SavedTrip {
         try? JSONDecoder().decode(Trip.self, from: tripData)
     }
 
-    var games: [UUID: RichGame] {
+    var games: [String: RichGame] {
         guard let data = gamesData else { return [:] }
-        return (try? JSONDecoder().decode([UUID: RichGame].self, from: data)) ?? [:]
+        return (try? JSONDecoder().decode([String: RichGame].self, from: data)) ?? [:]
     }
 
     var tripStatus: TripStatus {
         TripStatus(rawValue: status) ?? .draft
     }
 
-    static func from(_ trip: Trip, games: [UUID: RichGame] = [:], status: TripStatus = .planned) -> SavedTrip? {
+    static func from(_ trip: Trip, games: [String: RichGame] = [:], status: TripStatus = .planned) -> SavedTrip? {
         guard let tripData = try? JSONEncoder().encode(trip) else { return nil }
         let gamesData = try? JSONEncoder().encode(games)
         return SavedTrip(
@@ -75,7 +75,7 @@ final class TripVote {
     var tripId: UUID
     var voterId: String
     var voterName: String
-    var gameVotes: Data  // [UUID: Bool] encoded
+    var gameVotes: Data  // [String: Bool] encoded (game IDs to vote)
     var routeVotes: Data  // [String: Int] encoded
     var leisurePreference: String
     var createdAt: Date

SportsTime/Core/Models/Local/StadiumProgress.swift

@@ -65,8 +65,7 @@ final class StadiumVisit {
     @Attribute(.unique) var id: UUID
 
     // Stadium identity (stable across renames)
-    var canonicalStadiumId: String    // Links to CanonicalStadium.canonicalId
-    var stadiumUUID: UUID             // Runtime UUID for display lookups
+    var stadiumId: String             // Canonical ID: "stadium_mlb_fenway_park"
     var stadiumNameAtVisit: String    // Frozen at visit time
 
     // Visit details
@@ -75,9 +74,9 @@ final class StadiumVisit {
     var visitTypeRaw: String          // VisitType.rawValue
 
     // Game info (optional - nil for tours/other visits)
-    var gameId: UUID?
-    var homeTeamId: UUID?
-    var awayTeamId: UUID?
+    var gameId: String?               // Canonical ID: "game_mlb_2026_bos_nyy_0401"
+    var homeTeamId: String?           // Canonical ID: "team_mlb_bos"
+    var awayTeamId: String?           // Canonical ID: "team_mlb_nyy"
     var homeTeamName: String?         // For display when team lookup fails
     var awayTeamName: String?
     var finalScore: String?           // "5-3" format
@@ -109,15 +108,14 @@ final class StadiumVisit {
 
     init(
         id: UUID = UUID(),
-        canonicalStadiumId: String,
-        stadiumUUID: UUID,
+        stadiumId: String,
         stadiumNameAtVisit: String,
         visitDate: Date,
         sport: Sport,
         visitType: VisitType = .game,
-        gameId: UUID? = nil,
-        homeTeamId: UUID? = nil,
-        awayTeamId: UUID? = nil,
+        gameId: String? = nil,
+        homeTeamId: String? = nil,
+        awayTeamId: String? = nil,
         homeTeamName: String? = nil,
         awayTeamName: String? = nil,
         finalScore: String? = nil,
@@ -133,8 +131,7 @@ final class StadiumVisit {
         source: VisitSource = .manual
     ) {
         self.id = id
-        self.canonicalStadiumId = canonicalStadiumId
-        self.stadiumUUID = stadiumUUID
+        self.stadiumId = stadiumId
         self.stadiumNameAtVisit = stadiumNameAtVisit
         self.visitDate = visitDate
         self.sport = sport.rawValue