Add owned-games DTO and full profile support

Introduce SteamOwnedGamesResponse and SteamProfileAndGamesResponse DTOs and extend SteamApiService with getOwnedGames(...) and getFullPlayerProfile(...) to fetch and combine player summary and owned games. Update SteamTestController to return the combined profile/games response. Remove redundant Steam service URL entries from application.yml. Add SteamApiServiceTest to cover player summary, owned games (including null fields), and the combined profile flow; service falls back to empty lists on errors.

src/main/resources/application.yml

@@ -43,6 +43,4 @@ app:
   steam:
     api-key: ${STEAM_API_KEY}
     base-url: https://api.steampowered.com
-    playerService-url: https://api.steampowered.com/IPlayerService/GetOwnedGames/v1/
-    storeService-url: https://api.steampowered.com/IStoreService/GetAppList/v1/
     imageService-url: https://cdn.cloudflare.steamstatic.com/steam/apps/