feat(pricing): the server prices app orders with legacy's making-charge formula (MON-08)

Legacy: final % = variant % + customer % − the largest active promotion
on the product, its category or its brand; rial charge 0. The apps sent
the variant's own % only, so the new app undercharged by the customer's
percent (usually 3) and ignored promotions, and the server trusted
whatever the app sent.

- pricing/wage-formula.ts: one formula, legacy by default, with
  coefficients, promotion pick, constant, floor/cap and rounding so the
  admin screen can change it; validated
- an app order is priced by it; the app's wage, discount and rial charge
  are ignored; an operator's manual numbers are kept
- POST customer/me/wage-quote; both apps show that figure
- admin/pricing/wage-formula (config.wage): read, preview, approve with
  the sample it was checked on, last 20 versions kept; the setting is
  kept off the generic const routes

Owner approval: 2026-10-08.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/user-app/src/api/client.ts

@@ -303,6 +303,15 @@ export interface AccountingBalance {
   provider: string | null
 }
 
+/** POST /customer/me/wage-quote — one variant's making charge for the signed-in customer. */
+export interface WageQuote {
+  variantId: string
+  variantPercent: string
+  customerPercent: string
+  promotionPercent: string
+  finalPercent: string
+}
+
 export const api = {
   listProducts: () => request<ProductSummary[]>('/catalog/products'),
 
@@ -336,6 +345,9 @@ export const api = {
   getAccountingBalance: () => request<AccountingBalance>('/customer/me/accounting-balance'),
   getMyOrders: () => request<OrderDetail[]>('/customer/me/orders'),
   getMyLedgerEntries: () => request<LedgerEntrySummary[]>('/customer/me/ledger-entries'),
+  /** The making charge the server will charge for these variants (MON-08). */
+  getWageQuotes: (variantIds: string[]) =>
+    request<WageQuote[]>('/customer/me/wage-quote', { method: 'POST', body: JSON.stringify({ variantIds }) }),
   /** Favourite product ids, newest first — legacy get-favorites (FAV-01). */
   getFavorites: () => request<{ ids: string[] }>('/customer/me/favorites'),
   /** Legacy add-to-fav: adds or removes; answers the new state. */