feat: 用户徽章与等级体系，积分经济管理重构

- 新增徽章系统：badge 服务与 handler、管理端配置页、BadgeChip/LevelBadge 展示组件
- 新增等级模型：model/level 及前端 levels 元数据
- 管理端经济模块拆分为 points/badges/levels 独立页面，EconomySettings 迁入设置
- 积分、签到、评论等服务适配等级与徽章逻辑

frontend/app/admin/points/PointsTabs.tsx

@@ -0,0 +1,93 @@
+"use client";
+
+import { useCallback, useState } from "react";
+import { useRouter, useSearchParams } from "next/navigation";
+import { AdminSegmented } from "@/components/admin";
+import type { EconomyStats, PublicSettings } from "@/lib/api";
+import EconomyOverview from "./EconomyOverview";
+import EconomySettings from "../settings/EconomySettings";
+import UserPointsTab from "./UserPointsTab";
+
+type TabKey = "overview" | "rules" | "users";
+
+const TAB_OPTIONS = [
+  { key: "overview", label: "经济总览" },
+  { key: "rules", label: "积分规则" },
+  { key: "users", label: "用户积分" },
+];
+
+/**
+ * 积分管理页标签壳：经济总览（管理员及以上）/ 积分规则 + 用户积分（超管/站长）。
+ * tab 记在 URL query（?tab=）便于刷新/分享保持；三个面板保持挂载、用 display 切换，
+ * 避免切标签丢失规则的未保存修改与用户列表状态。
+ */
+export default function PointsTabs({
+  stats,
+  settings,
+  canManage,
+}: {
+  stats: EconomyStats | null;
+  settings: PublicSettings | null;
+  canManage: boolean;
+}) {
+  const router = useRouter();
+  const searchParams = useSearchParams();
+  const queryTab = searchParams.get("tab");
+  const [tab, setTab] = useState<TabKey>(() => {
+    const t = queryTab;
+    if (canManage && (t === "rules" || t === "users")) return t;
+    return "overview";
+  });
+
+  const switchTab = useCallback(
+    (next: string) => {
+      setTab(next as TabKey);
+      const params = new URLSearchParams(searchParams.toString());
+      if (next === "overview") params.delete("tab");
+      else params.set("tab", next);
+      const qs = params.toString();
+      router.replace(qs ? `?${qs}` : "?", { scroll: false });
+    },
+    [router, searchParams]
+  );
+
+  const options = canManage
+    ? TAB_OPTIONS
+    : TAB_OPTIONS.filter((o) => o.key === "overview");
+
+  return (
+    <div>
+      {canManage ? (
+        <div className="mb-4">
+          <AdminSegmented
+            options={options}
+            value={tab}
+            onChange={(v) => switchTab(String(v))}
+            ariaLabel="积分管理标签"
+          />
+        </div>
+      ) : null}
+
+      {/* 各面板保持挂载（display 切换）：规则未保存修改与用户列表状态不因切标签丢失 */}
+      <div style={tab === "overview" ? undefined : { display: "none" }}>
+        {stats ? (
+          <EconomyOverview stats={stats} />
+        ) : (
+          <div className="panel p-8 text-center">
+            <p className="meta">暂时无法加载积分数据</p>
+          </div>
+        )}
+      </div>
+      {canManage ? (
+        <>
+          <div style={tab === "rules" ? undefined : { display: "none" }}>
+            {settings ? <EconomySettings initial={settings} /> : null}
+          </div>
+          <div style={tab === "users" ? undefined : { display: "none" }}>
+            <UserPointsTab />
+          </div>
+        </>
+      ) : null}
+    </div>
+  );
+}