[chestshop] Migrate to a service/DAO architecture (strangler-fig away from the event-bus pipelines)

Phase 2 done (commit 7d0dc3f): account domain migrated. NameManager static God-class split into AccountRepository + SqliteAccountRepository (users.db persistence behind a storage-agnostic contract) and AccountService (@Singleton: caches, get-or-create, shortened-name allocation, admin/server-economy accounts, canUseName, load()), reached via ChestShop.accounts(). NameManager is now a thin Listener (the AccountQuery/AccountAccess events stay — Treasury integration points) plus a delegating static facade so the ~25 callers compile unchanged. Added AccountServiceTest (row-count + shortened-name disambiguation now unit-testable over a fake repo). Builds + tests green.

Remaining: ShopService for creation/removal (Phase 2-shops), migrate the ~25 callers off the NameManager facade and delete it, then delete the dead event scaffolding (Phase 3).

Phase 2-shops done (commit 2f8e28f): ShopService extracted. Shops have no ChestShop-owned persistence (sign+chest world state; only DB is Treasury's external MarketApi), so no repository — just a service owning the lifecycle money logic that was embedded in listeners: chargeCreationFee(player, signLines) (fee + server-economy credit + message, returns whether creation proceeds) and refundOnRemoval(destroyer, sign) (refund + server-economy debit + message). CreationFeeGetter and ShopRefundListener are now thin entrypoints delegating via ChestShop.shops(). Money still flows through the Currency*Event integration points. The 12-listener creation-validation pipeline + market sync stay as events (deliberately — integration/coordination, Phase 3). Builds + tests green.

Remaining: migrate the ~25 callers off the NameManager static facade and delete it (split its 2 @EventHandlers into a thin AccountListener); then Phase 3 — assess collapsing the internal-only validation scaffolding (PreShopCreationEvent pipeline) now that the money logic is out.

NameManager facade deleted (commit 5d68858): account-domain migration complete. The ~25 callers across the economy/sign-creation/removal/command paths now call AccountService directly via ChestShop.accounts(); the two account @EventHandlers moved to a thin AccountListener (registered in place of the old NameManager listener). Pure delegator removal, no behaviour change. Builds + tests green.

Remaining: Phase 3 — assess whether the now internal-only shop-creation validation scaffolding (PreShopCreationEvent + the 12 preshopcreation listeners) is worth collapsing into the ShopService, now that the money logic is out and the genuine integration events (AccountQuery/AccountAccess, Currency*, ShopCreated/Destroyed→Market) are clearly separated.