feat(sync): update CloudKit sync methods to use modificationDate delta

- fetchStadiumsForSync now accepts since: Date? parameter
- fetchTeamsForSync changed from per-sport to all teams with delta sync
- fetchGamesForSync uses modificationDate instead of game dateTime

When lastSync is nil, fetches all records (first sync).
When lastSync has value, fetches only modified records (delta sync).

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

SportsTime/Core/Services/CloudKitService.swift

@@ -213,9 +213,15 @@ actor CloudKitService {
 
     // MARK: - Sync Fetch Methods (return canonical IDs directly from CloudKit)
 
-    /// Fetch stadiums with canonical IDs for sync operations
+    /// Fetch stadiums for sync operations
-    func fetchStadiumsForSync() async throws -> [SyncStadium] {
+    /// - Parameter lastSync: If nil, fetches all stadiums. If provided, fetches only stadiums modified since that date.
-        let predicate = NSPredicate(value: true)
+    func fetchStadiumsForSync(since lastSync: Date?) async throws -> [SyncStadium] {
+        let predicate: NSPredicate
+        if let lastSync = lastSync {
+            predicate = NSPredicate(format: "modificationDate >= %@", lastSync as NSDate)
+        } else {
+            predicate = NSPredicate(value: true)
+        }
         let query = CKQuery(recordType: CKRecordType.stadium, predicate: predicate)
 
         let (results, _) = try await publicDatabase.records(matching: query)
@@ -230,9 +236,15 @@ actor CloudKitService {
         }
     }
 
-    /// Fetch teams with canonical IDs for sync operations
+    /// Fetch teams for sync operations
-    func fetchTeamsForSync(for sport: Sport) async throws -> [SyncTeam] {
+    /// - Parameter lastSync: If nil, fetches all teams. If provided, fetches only teams modified since that date.
-        let predicate = NSPredicate(format: "sport == %@", sport.rawValue)
+    func fetchTeamsForSync(since lastSync: Date?) async throws -> [SyncTeam] {
+        let predicate: NSPredicate
+        if let lastSync = lastSync {
+            predicate = NSPredicate(format: "modificationDate >= %@", lastSync as NSDate)
+        } else {
+            predicate = NSPredicate(value: true)
+        }
         let query = CKQuery(recordType: CKRecordType.team, predicate: predicate)
 
         let (results, _) = try await publicDatabase.records(matching: query)
@@ -248,37 +260,29 @@ actor CloudKitService {
         }
     }
 
-    /// Fetch games with canonical IDs for sync operations
+    /// Fetch games for sync operations
-    func fetchGamesForSync(
+    /// - Parameter lastSync: If nil, fetches all games. If provided, fetches only games modified since that date.
-        sports: Set<Sport>,
+    func fetchGamesForSync(since lastSync: Date?) async throws -> [SyncGame] {
-        startDate: Date,
+        let predicate: NSPredicate
-        endDate: Date
+        if let lastSync = lastSync {
-    ) async throws -> [SyncGame] {
+            predicate = NSPredicate(format: "modificationDate >= %@", lastSync as NSDate)
-        var allGames: [SyncGame] = []
+        } else {
-
+            predicate = NSPredicate(value: true)
-        for sport in sports {
+        }
-            let predicate = NSPredicate(
-                format: "sport == %@ AND dateTime >= %@ AND dateTime <= %@",
-                sport.rawValue,
-                startDate as NSDate,
-                endDate as NSDate
-            )
         let query = CKQuery(recordType: CKRecordType.game, predicate: predicate)
 
         let (results, _) = try await publicDatabase.records(matching: query)
 
-            let games = results.compactMap { result -> SyncGame? in
+        return results.compactMap { result -> SyncGame? in
             guard case .success(let record) = result.1 else { return nil }
             let ckGame = CKGame(record: record)
 
-                // Extract canonical IDs directly from CloudKit
             guard let canonicalId = ckGame.canonicalId,
                   let homeTeamCanonicalId = ckGame.homeTeamCanonicalId,
                   let awayTeamCanonicalId = ckGame.awayTeamCanonicalId,
                   let stadiumCanonicalId = ckGame.stadiumCanonicalId
             else { return nil }
 
-                // For the Game domain object, use canonical IDs directly
             guard let game = ckGame.game(
                 homeTeamId: homeTeamCanonicalId,
                 awayTeamId: awayTeamCanonicalId,
@@ -292,12 +296,7 @@ actor CloudKitService {
                 awayTeamCanonicalId: awayTeamCanonicalId,
                 stadiumCanonicalId: stadiumCanonicalId
             )
-            }
+        }.sorted { $0.game.dateTime < $1.game.dateTime }
-
-            allGames.append(contentsOf: games)
-        }
-
-        return allGames.sorted { $0.game.dateTime < $1.game.dateTime }
     }
 
     // MARK: - League Structure & Team Aliases