Eliminate the last three direct DB accesses from handler code:
- CharacterRepo.LoadSaveData: replaces db.Query in GetCharacterSaveData,
using QueryRow instead of Query+Next for cleaner single-row access
- EventRepo.GetEventQuests, UpdateEventQuestStartTime, BeginTx: moves
event quest enumeration and rotation queries behind the repo layer
- UserRepo.BanUser: consolidates permanent/temporary ban upserts into a
single method with nil/*time.Time semantics
Replace concrete pointer types on the Server struct with interfaces to
decouple handlers from PostgreSQL implementations. This enables mock/stub
injection for unit tests and opens the door to alternative storage
backends (SQLite, in-memory).
Also adds 9 missing repo initializations to SetTestDB() (event,
achievement, shop, cafe, goocoo, diva, misc, scenario, mercenary)
to match NewServer().
