loyalty-plugin: let the application opt out of the plugin's core workflow hooks, and export its order workflows

[b0dea]

@medusajs/loyalty-plugin registers handlers on four core workflow hooks at module load. A hook takes one handler, so once the plugin is installed the application can't register its own handler on any of them, and the plugin has no option to leave them to the application. This is a narrower, plugin-level ask than #11968 (multiple handlers per hook, closed as not planned).

Plugin file (src/workflows/hooks/)	Hook	Workflow it runs
after-order-created.ts	completeCartWorkflow.hooks.orderCreated	cloneCartGiftCardsToOrderWorkflow
complete-cart-before-payment-authorization.ts	completeCartWorkflow.hooks.beforePaymentAuthorization	confirmCartCreditLinesWorkflow
after-order-credit-lines-created.ts	createOrderCreditLinesWorkflow.hooks.creditLinesCreated	refundCreditLinesWorkflow
before-payment-collection-refresh.ts	refreshCartItemsWorkflow.hooks.beforeRefreshingPaymentCollection	refreshCartGiftCardsWorkflow

Repro (2.22.0, same on develop): register the plugin, then add any handler on one of those hooks:

// src/workflows/hooks/order-created.ts
import { completeCartWorkflow } from "@medusajs/medusa/core-flows"

completeCartWorkflow.hooks.orderCreated(async ({ order_id }) => {
  // application logic
})

medusa develop fails with Cannot define multiple hook handlers for the orderCreated hook.

The application also can't take a hook over and call the plugin's workflow from its own handler, because two of the four workflows aren't public: @medusajs/loyalty-plugin/workflows exports carts, gift-cards and store-credit, but not orders, which holds cloneCartGiftCardsToOrderWorkflow and refundCreditLinesWorkflow.

Ask

1. A way to opt out of the plugin's hook registrations, e.g. a plugin option like registerHooks: false, or moving the registrations into an exported function the application calls (default behaviour unchanged). It would help if the docs then listed which workflows the application has to run from its own handlers.
2. Export every workflow the hook handlers run. That part is one line in packages/plugins/loyalty/src/workflows/index.ts: export * from "./orders".

How plugin options should reach module-load code is your call, so I've left the opt-out shape open.

Current workaround: a package patch that empties the plugin's four hook files and adds the orders export, with our own single handler per hook running the plugin's workflows next to our logic. Patching compiled output has to be redone on every release, which is why we'd rather have a supported switch.