feat(orders): migrate orders to backend API

tests/orders-api.test.ts

@@ -3,14 +3,16 @@ import { useAuthStore } from "@/store/auth"
 import { describe, expect, it } from "vitest"
 
 describe("lib/api/orders", () => {
-  it("returns { decision: { ok:false, error:{code,msg} } } when unauthenticated", () => {
+  it("returns { decision: { ok:false, error:{code,msg} } } when unauthenticated", async () => {
     useAuthStore.getState().logout()
 
-    const res = createPaidOrder({
-      playerId: "1005",
-      serviceId: "5001",
-      quantity: 1,
-    })
+    const res = await Promise.resolve(
+      createPaidOrder({
+        playerId: "1005",
+        serviceId: "5001",
+        quantity: 1,
+      }),
+    )
 
     expect(res).toEqual({
       decision: {