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/lib/badgeIcons.ts

@@ -0,0 +1,47 @@
+import type { LucideIcon } from "lucide-react";
+import {
+  Medal,
+  Award,
+  Trophy,
+  Crown,
+  Star,
+  Heart,
+  Zap,
+  Flame,
+  Gem,
+  Shield,
+  Rocket,
+  Sparkles,
+  ThumbsUp,
+  BookOpen,
+  Code,
+  Wrench,
+} from "lucide-react";
+
+/**
+ * 徽章图标白名单：后台管理以 lucide 图标名存储，前端仅渲染此表内的图标，
+ * 未知/空名回落 Medal（与后端 model.Badge.Icon 注释约定一致）。
+ */
+export const BADGE_ICONS: Record<string, LucideIcon> = {
+  medal: Medal,
+  award: Award,
+  trophy: Trophy,
+  crown: Crown,
+  star: Star,
+  heart: Heart,
+  zap: Zap,
+  flame: Flame,
+  gem: Gem,
+  shield: Shield,
+  rocket: Rocket,
+  sparkles: Sparkles,
+  thumbs_up: ThumbsUp,
+  book_open: BookOpen,
+  code: Code,
+  wrench: Wrench,
+};
+
+/** 取徽章图标组件；未知/空名回落 Medal */
+export function badgeIcon(name?: string | null): LucideIcon {
+  return (name && BADGE_ICONS[name]) || Medal;
+}