feat(config): 更新环境配置与 API 处理逻辑

修改 .env.example，补充环境切换说明并新增生产环境 API 地址配置。
更新 next.config.ts：使用 API_BASE_URL 进行 API 重写配置，确保 API 路由一致性。
重构 login-form.tsx：移除 API 配置检查逻辑，简化登录流程。
调整 admin-http.ts：通过 Next.js 代理转发 API 请求，提升后端通信稳定性。

src/components/admin/login-form.tsx

@@ -1,13 +1,12 @@
 "use client";
 
-import { ShieldCheckIcon, TriangleAlertIcon } from "lucide-react";
+import { ShieldCheckIcon } from "lucide-react";
 import { useRouter } from "next/navigation";
 import { useCallback, useEffect, useState } from "react";
 import { useTranslation } from "react-i18next";
 import { toast } from "sonner";
 import { isAxiosError } from "axios";
 
-import { Alert, AlertDescription, AlertTitle } from "@/components/ui/alert";
 import { AdminLanguageSwitcher } from "@/components/admin/admin-language-switcher";
 import { Button } from "@/components/ui/button";
 import { Card, CardContent, CardFooter, CardHeader, CardTitle } from "@/components/ui/card";
@@ -25,10 +24,6 @@ export function LoginForm() {
   const setBearerToken = useAdminSessionStore((s) => s.setBearerToken);
   const setAdminProfile = useAdminSessionStore((s) => s.setAdminProfile);
 
-  const apiConfigured =
-    process.env.NEXT_PUBLIC_LOTTERY_API_BASE_URL?.trim() !== "" &&
-    process.env.NEXT_PUBLIC_LOTTERY_API_BASE_URL !== undefined;
-
   const [account, setAccount] = useState("");
   const [password, setPassword] = useState("");
   const [captchaCode, setCaptchaCode] = useState("");
@@ -39,9 +34,6 @@ export function LoginForm() {
   const [submitting, setSubmitting] = useState(false);
 
   const loadCaptcha = useCallback(async () => {
-    if (!apiConfigured) {
-      return;
-    }
     setLoadingCaptcha(true);
     try {
       const data = await getAdminCaptcha();
@@ -58,7 +50,7 @@ export function LoginForm() {
     } finally {
       setLoadingCaptcha(false);
     }
-  }, [apiConfigured, t]);
+  }, [t]);
 
   useEffect(() => {
     if (readToken()) {
@@ -75,11 +67,6 @@ export function LoginForm() {
 
   async function onSubmit(e: React.FormEvent<HTMLFormElement>) {
     e.preventDefault();
-    if (!apiConfigured) {
-      toast.error(t("apiBaseMissingToast"));
-
-      return;
-    }
     if (!captchaKey || !captchaSrc) {
       toast.error(t("captchaRequired"));
       void loadCaptcha();
@@ -156,19 +143,6 @@ export function LoginForm() {
         </CardHeader>
         <form onSubmit={onSubmit}>
           <CardContent className="flex flex-col gap-5 sm:px-8">
-            {!apiConfigured ? (
-              <Alert variant="destructive" className="text-left">
-                <TriangleAlertIcon />
-                <AlertTitle>{t("apiMissingTitle")}</AlertTitle>
-                <AlertDescription>
-                  {t("apiMissingDescriptionPrefix")}{" "}
-                  <code className="rounded bg-muted px-1 py-0.5 text-xs">
-                    NEXT_PUBLIC_LOTTERY_API_BASE_URL
-                  </code>{" "}
-                  {t("apiMissingDescriptionSuffix")}
-                </AlertDescription>
-              </Alert>
-            ) : null}
             <div className="flex flex-col gap-2">
               <Label htmlFor="admin-account" className="text-sm font-medium">
                 {t("account")}
@@ -224,7 +198,7 @@ export function LoginForm() {
                   className="flex h-11 min-w-[156px] shrink-0 cursor-pointer items-center justify-center overflow-hidden rounded-xl border border-border/80 bg-muted/35 px-2 shadow-[inset_0_1px_2px_rgba(0,0,0,0.04)] ring-1 ring-black/[0.03] transition-[box-shadow,transform] hover:bg-muted/45 active:scale-[0.98] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary/30 disabled:pointer-events-none disabled:opacity-50 dark:bg-muted/25 dark:shadow-[inset_0_1px_2px_rgba(0,0,0,0.2)] dark:ring-white/[0.06] dark:hover:bg-muted/35"
                   onClick={() => void loadCaptcha()}
                   disabled={
-                    loadingCaptcha || !apiConfigured || submitting
+                    loadingCaptcha || submitting
                   }
                   aria-label={loadingCaptcha ? t("captchaLoading") : t("captchaRefresh")}
                 >
@@ -251,7 +225,7 @@ export function LoginForm() {
               type="submit"
               size="lg"
               className="h-11 w-full text-base font-medium shadow-sm"
-              disabled={submitting || !apiConfigured}
+              disabled={submitting}
             >
               {submitting ? t("submitting") : t("submit")}
             </Button>

src/lib/admin-http.ts

@@ -9,15 +9,13 @@ import { withAdminLocaleHeaders } from "@/lib/admin-locale";
 import { LotteryApiBizError, LotteryApiEnvelopeError } from "@/types/api/errors";
 import { isApiEnvelope } from "@/types/api/envelope";
 
-const baseURL = process.env.NEXT_PUBLIC_LOTTERY_API_BASE_URL?.trim();
-
-/** 是否已配置后台 API 根地址（客户端/服务端均可用 `NEXT_PUBLIC_*`） */
 export function hasLotteryAdminApiBaseUrl(): boolean {
-  return baseURL !== undefined && baseURL !== "";
+  return true;
 }
 
 export const adminHttp = axios.create({
-  baseURL: baseURL && baseURL !== "" ? baseURL : undefined,
+  // 统一走 Next 同源 /api 代理，由 next.config.ts 的 API_BASE_URL 转发到后端。
+  baseURL: "/api",
   timeout: 30_000,
   headers: { Accept: "application/json" },
 });