feat: 可配置站点 URL 风格

- 新增 urlStyle 工具与测试：postPath/userPath/sitePagePath 统一生成链接
- 管理端新增 UrlStylePanel 设置面板，settings 服务与 handler 适配
- 全站路由链接与 JSON-LD/sitemap 切换为统一 URL 生成
- middleware 与相关组件适配

frontend/lib/api.ts

@@ -13,6 +13,7 @@ import {
   type FooterLinksAlign,
 } from "./brand";
 import { DEFAULT_LEVEL_DEFS, LEVEL_COLOR_KEYS, MAX_LEVEL_COUNT, type LevelDef } from "./levels";
+import { normalizeUrlStyle, type UrlStyle } from "./urlStyle";
 import { CSRF_COOKIE, hasAuthCookieHint } from "./cookies";
 import { publishPublicMetaSnapshot } from "./publicMetaSnapshot";
 import { emitForceLogout } from "./userEvents";
@@ -1009,6 +1010,8 @@ export interface PublicSettings {
   levels: LevelDef[];
   /** 等级特效动画总开关（流光动画）；缺省开 */
   levels_fx: boolean;
+  /** 详情页伪静态风格；缺省 default（标准 /post/123） */
+  url_style: UrlStyle;
 }
 
 /** 与后端 DefaultAttachmentExts 保持同步 */
@@ -1073,6 +1076,7 @@ const DEFAULT_PUBLIC_SETTINGS: PublicSettings = {
   necro_reply_penalty: 0,
   levels: [...DEFAULT_LEVEL_DEFS],
   levels_fx: true,
+  url_style: "default",
 };
 
 function normalizeAttachmentExts(raw: unknown): string[] {
@@ -1160,6 +1164,7 @@ function normalizePublicSettings(data: Partial<PublicSettings> | null | undefine
     bg_admin_mode: typeof data?.bg_admin_mode === "string" ? data.bg_admin_mode : "cover",
     ...normalizePointsSettings(data),
     ...normalizeLockSettings(data),
+    url_style: normalizeUrlStyle(data?.url_style),
     levels: normalizeLevels(data?.levels),
     levels_fx: data?.levels_fx !== false,
   };
@@ -3361,6 +3366,7 @@ export type UpdateSiteSettingsBody = {
   footer_links?: FooterLink[];
   allow_register?: boolean;
   allow_comments?: boolean;
+  url_style?: UrlStyle;
   comments_require_login?: boolean;
   allow_messages?: boolean;
   post_cooldown_hours?: number;