Move scan loops from handlers into repository methods so that interfaces
return typed slices instead of leaking database cursors. This fixes
resource leaks (7 of 12 call sites never closed rows) and makes all
12 methods mockable for unit tests.
Affected repos: CafeRepo, ShopRepo, EventRepo, RengokuRepo, DivaRepo,
ScenarioRepo, MiscRepo, MercenaryRepo. New structs: DivaEvent,
MercenaryLoan, GuildHuntCatUsage. EventRepo.GetEventQuests left as-is
(requires broader Server refactor).
Move remaining raw s.server.db.* queries from handler files into
dedicated repository structs, completing the repository extraction
effort. Also adds SaveCharacterData and SaveHouseData to
CharacterRepository.
Fixes guild_hunts query to select both cats_used and start columns
to match the existing two-column Scan call. Adds slot index
validation in GoocooRepository to prevent SQL injection via
fmt.Sprintf.
