fix(frontend): errorCode 统一自 generation/cards 去重复定义（CR-H10）

apps/web/lib/style/useRefine.ts

@@ -4,6 +4,7 @@ import { useCallback, useState } from "react";
 
 import { api } from "@/lib/api/client";
 import { useToast } from "@/components/Toast";
+import { errorCode } from "@/lib/generation/cards";
 import { buildRefineRequest } from "./style";
 
 export type RefineStatus = "idle" | "refining" | "done" | "error";
@@ -26,12 +27,6 @@ export interface UseRefine {
   reset: () => void;
 }
 
-function errorCode(error: unknown): string | undefined {
-  if (typeof error !== "object" || error === null) return undefined;
-  const env = error as { error?: { code?: unknown } };
-  return typeof env.error?.code === "string" ? env.error.code : undefined;
-}
-
 // 回炉（POST .../refine）：同步返回新旧 diff，不写库（不变量#3）。
 // 503 LLM_UNAVAILABLE（无凭据）优雅提示去设置；其余失败 toast。
 export function useRefine(): UseRefine {