feat: add local auth billing and usage management

app/api/admin/billing/account/route.ts

@@ -0,0 +1,27 @@
+import { jsonError, jsonOk, readJsonBody } from "@/lib/server/api";
+import { requireSuperAdminUser } from "@/lib/server/auth/current-user";
+import { getBillingAccountConfig } from "@/lib/server/billing-service";
+import { saveApiSettings } from "@/lib/server/app-settings";
+
+export const runtime = "nodejs";
+
+export async function PATCH(request: Request) {
+  try {
+    await requireSuperAdminUser();
+    const body = await readJsonBody<Record<string, unknown>>(request);
+    const values = {
+      ZHINIAN_BILLING_ACCOUNT_NAME: normalize(body.accountName),
+      ZHINIAN_BILLING_ACCOUNT_BANK: normalize(body.bankName),
+      ZHINIAN_BILLING_ACCOUNT_NUMBER: normalize(body.accountNumber),
+      ZHINIAN_BILLING_CONTACT: normalize(body.contact)
+    };
+    await saveApiSettings(values);
+    return jsonOk({ billingAccount: getBillingAccountConfig() });
+  } catch (error) {
+    return jsonError(error, 500, { request, source: "api.admin.billing.account" });
+  }
+}
+
+function normalize(value: unknown): string {
+  return typeof value === "string" ? value.trim() : "";
+}