增加统一倍率调整按钮

tests/billing-http-contract.test.ts

@@ -11,6 +11,7 @@ describe("billing HTTP compatibility fixture", () => {
     });
     expect(fixture.routes).toEqual(expect.arrayContaining([
       expect.objectContaining({ method: "GET", path: "/api/billing", organizationSource: "refreshed_session" }),
+      expect.objectContaining({ method: "PATCH", path: "/api/admin/billing/prices", requirement: "super_admin", allowedFields: ["ruleIds", "markupMultiplier"], atomic: true }),
       expect.objectContaining({ method: "PATCH", path: "/api/admin/billing/prices/{id}", requirement: "super_admin" })
     ]));
   });