feat: 外观支持自定义 CSS/JS，并升级发帖工作台与积分存量看板

后台可注入全站 CSS/JS（SSR 生效，CSS 可热换）；发帖/编辑改为锁一屏工作室；经济看板增加存量健康度；主题令牌与弹层误关一并收紧。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/lib/postMeta.ts

@@ -1,11 +1,11 @@
 /** 帖子类型 / 可见性 / 展示文案（前后端共用约定） */
 
 export const POST_TYPES = [
-  { value: "discussion", label: "讨论", hint: "默认讨论帖" },
+  { value: "discussion", label: "讨论", hint: "日常交流" },
   { value: "question", label: "问答", hint: "提问求解" },
-  { value: "poll", label: "投票", hint: "发起投票，读者可参与" },
-  { value: "bounty", label: "悬赏", hint: "发布时托管积分，采纳后发放" },
-  { value: "lottery", label: "抽奖", hint: "奖品类型+数量入池，评论后锁定奖品" },
+  { value: "poll", label: "投票", hint: "收集选项意见" },
+  { value: "bounty", label: "悬赏", hint: "积分托管求解" },
+  { value: "lottery", label: "抽奖", hint: "评论参与开奖" },
 ] as const;
 
 export type PostTypeValue = (typeof POST_TYPES)[number]["value"];