Adopt HiberniaModule bootstrap + 1.2.0 quick wins (treasury-api-plugin)

Migrate treasury-api-plugin's hand-rolled DI (TreasuryAPIModule + CommanderModule + manual ConfigurationLoader, TreasuryAPI.java:29,74-78) to HiberniaModule.forPlugin(...).scanConfiguration("io.paradaux.treasuryapi.model.config").handlers(TreasuryAPICommand.class).build(). Keep a small module for the plugin-specific bindings HiberniaModule doesn't cover: TreasuryApi/BusinessApi toInstance, optional LuckPerms (TreasuryAPIModule:66-72), service bindings (:53-61). DatabaseModule stays. Preserve the early ApiConfiguration JWT-secret guard (TreasuryAPI:41-50) via hibernia.configuration(ApiConfiguration.class), and the Injector self-injection in UiAccessHandler:39. Activates DefaultsReconciler (valuable for this message-heavy plugin).

Quick wins: add /treasuryapi help via HelpGenerator (no help command today; rich @Descriptions already present); add a reload-trap guard comment (no reload path today, toInstance bindings are the anti-pattern under 1.2.0). No BigDecimal target. Deferred: KeyedException localization (ApiKeyServiceImpl raw IllegalArgumentException).