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/u/[id]/page.tsx

@@ -17,6 +17,8 @@ import PasswordForm from "./PasswordForm";
 import LoginDevices from "./LoginDevices";
 import ProfileHeroAvatar from "./ProfileHeroAvatar";
 import RoleBadge from "@/components/RoleBadge";
+import LevelBadge from "@/components/LevelBadge";
+import BadgeChip from "@/components/BadgeChip";
 import { roleMeta } from "@/lib/roles";
 import StartDMButton from "./StartDMButton";
 import StaffUserMenu from "@/components/StaffUserMenu";
@@ -253,6 +255,7 @@ export default async function UserPage({ params, searchParams }: UserPageProps)
               >
                 {u.nickname || u.username}
               </h1>
+              <LevelBadge level={u.level} />
               {u.role !== "user" && (
                 <RoleBadge role={u.role} boardIds={u.board_ids} />
               )}
@@ -265,6 +268,18 @@ export default async function UserPage({ params, searchParams }: UserPageProps)
                 </span>
               )}
             </div>
+            {/* 徽章墙：管理员颁布的全部徽章，悬浮显示授予时间 */}
+            {(u.badges ?? []).length > 0 && (
+              <div className="mt-1.5 flex items-center gap-1.5 flex-wrap">
+                {(u.badges ?? []).map((ub) => (
+                  <BadgeChip
+                    key={ub.id}
+                    badge={ub.badge}
+                    tip={`${ub.badge.name} · ${new Date(ub.awarded_at).toLocaleDateString("zh-CN")} 颁布`}
+                  />
+                ))}
+              </div>
+            )}
             <p className="mt-1.5 text-[14px] leading-snug flex flex-wrap items-center" style={{ color: "var(--ink-2)" }}>
               <span>
                 <span className="tabular-nums font-semibold" style={{ color: "var(--ink)" }}>{data.stats.post_count}</span>