KeyQuest set, Rights, and Teleport commands silently used zero values
when given malformed arguments (bad hex, non-integer coords). Now they
send the existing i18n error messages back to the player instead.
Several handler files discarded errors from repository and service
calls, creating nil-dereference risks and silent data corruption:
- guild_adventure: 3 GetByCharID calls could panic on nil guild
- gacha: GetGachaPoints silently returned zero balances on DB error
- house: HasApplication called before nil check on guild;
GetHouseContents error discarded with 7 return values
- distitem: 3 distRepo calls had no error logging
- guild_ops: Disband/Leave service errors were invisible
- shop: gacha type/weight/fpoint lookups had no error logging
- discord: bcrypt error could result in nil password being set
