add TEMPORARY winner getter and setter methods to match_dao.dart

lib/data/dao/match_dao.dart

@@ -339,4 +339,40 @@ class MatchDao extends DatabaseAccessor<AppDatabase> with _$MatchDaoMixin {
     );
     return rowsAffected > 0;
   }
+
+  // ============================================================
+  // TEMPORARY: Winner methods - these are stubs and do not persist data
+  // TODO: Implement proper winner handling
+  // ============================================================
+
+  /// TEMPORARY: Checks if a match has a winner.
+  /// Currently returns true if the match has any players.
+  Future<bool> hasWinner({required String matchId}) async {
+    final players = await db.playerMatchDao.getPlayersOfMatch(matchId: matchId);
+    return players?.isNotEmpty ?? false;
+  }
+
+  /// TEMPORARY: Gets the winner of a match.
+  /// Currently returns the first player in the match's player list.
+  Future<Player?> getWinner({required String matchId}) async {
+    final players = await db.playerMatchDao.getPlayersOfMatch(matchId: matchId);
+    return (players?.isNotEmpty ?? false) ? players!.first : null;
+  }
+
+  /// TEMPORARY: Sets the winner of a match.
+  /// Currently does nothing - winner is not persisted.
+  Future<bool> setWinner({
+    required String matchId,
+    required String winnerId,
+  }) async {
+    // TODO: Implement winner persistence
+    return true;
+  }
+
+  /// TEMPORARY: Removes the winner of a match.
+  /// Currently does nothing - winner is not persisted.
+  Future<bool> removeWinner({required String matchId}) async {
+    // TODO: Implement winner persistence
+    return true;
+  }
 }

lib/data/dto/match.dart

@@ -12,6 +12,7 @@ class Match {
   final Group? group;
   final List<Player>? players;
   final String? notes;
+  Player? winner;
 
   Match({
     String? id,
@@ -21,12 +22,13 @@ class Match {
     this.group,
     this.players,
     this.notes,
+    this.winner,
   }) : id = id ?? const Uuid().v4(),
        createdAt = createdAt ?? clock.now();
 
   @override
   String toString() {
-    return 'Match{id: $id, name: $name, game: $game, group: $group, players: $players, notes: $notes}';
+    return 'Match{id: $id, name: $name, game: $game, group: $group, players: $players, notes: $notes, winner: $winner}';
   }
 
   /// Creates a Match instance from a JSON object.