feat: Enhance pricing and sales API with free goods and discount scheme support

distribution_fe/lib/api/pricing.ts

@@ -4,6 +4,7 @@ import type {
   PriceResolution,
   SchemeResponse,
   SchemeRuleType,
+  SchemeSuggestion,
 } from '@/types/api'
 
 // ─── Price Lists ──────────────────────────────────────────────────────────────
@@ -89,4 +90,17 @@ export const schemes = {
 
   remove: (id: string) =>
     api.delete(`/schemes/${id}`),
+
+  setFreeGoodsRule: (id: string, body: { triggerItemId?: string | null; triggerQty?: number | null; freeItemId: string; freeQty: number }) =>
+    api.put<SchemeResponse>(`/schemes/${id}/free-goods-rule`, body).then(r => r.data),
+
+  upsertBundleComponent: (id: string, itemId: string, qty: number) =>
+    api.put<SchemeResponse>(`/schemes/${id}/bundle-components/${itemId}`, { qty }).then(r => r.data),
+
+  removeBundleComponent: (id: string, itemId: string) =>
+    api.delete<SchemeResponse>(`/schemes/${id}/bundle-components/${itemId}`).then(r => r.data),
+
+  /** Schemes the lines of a not-yet-saved Shop PO qualify for (or are close to). */
+  suggest: (body: { storeId: string; items: { itemId: string; quantity: number; unitPrice?: number | null }[] }) =>
+    api.post<SchemeSuggestion[]>('/schemes/suggest', body).then(r => r.data),
 }