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/app/globals.css

@@ -4590,11 +4590,13 @@ a.j13-mention-token:hover {
   }
   #settings-identity .admin-settings-actions,
   #settings-brand .admin-settings-actions,
+  #settings-url-style .admin-settings-actions,
   #settings-footer .admin-settings-actions {
     grid-template-columns: minmax(0, 1fr);
   }
   #settings-identity .admin-settings-actions-inner,
   #settings-brand .admin-settings-actions-inner,
+  #settings-url-style .admin-settings-actions-inner,
   #settings-footer .admin-settings-actions-inner {
     grid-column: 1;
   }
@@ -4860,6 +4862,71 @@ a.j13-mention-token:hover {
     }
   }
 
+  /* 链接风格（伪静态）三选卡 */
+  .admin-url-style-card {
+    display: flex;
+    flex-direction: column;
+    align-items: stretch;
+    padding: 0.8rem 0.85rem;
+    border-radius: 12px;
+    border: 1px solid var(--line);
+    background: var(--panel);
+    text-align: left;
+    cursor: pointer;
+    font: inherit;
+    color: inherit;
+    transition: border-color 0.15s ease, box-shadow 0.15s ease;
+  }
+  .admin-url-style-card.is-on {
+    border-color: color-mix(in srgb, var(--accent) 55%, var(--line));
+    box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 45%, transparent);
+  }
+  .admin-url-style-card:focus-visible {
+    outline: 2px solid var(--accent);
+    outline-offset: 1px;
+  }
+  .admin-url-style-dot {
+    width: 0.85rem;
+    height: 0.85rem;
+    border-radius: 999px;
+    border: 1px solid var(--line-2);
+    background: var(--panel-2);
+    flex-shrink: 0;
+  }
+  .admin-url-style-dot.is-on {
+    border-color: var(--accent);
+    background: radial-gradient(circle, var(--accent) 0 42%, transparent 46%);
+  }
+  .admin-url-style-examples {
+    display: flex;
+    flex-direction: column;
+    gap: 0.25rem;
+    margin-top: 0.6rem;
+    padding: 0.55rem 0.6rem;
+    border-radius: 8px;
+    background: var(--panel-2);
+  }
+  .admin-url-style-example {
+    display: flex;
+    align-items: baseline;
+    justify-content: space-between;
+    gap: 0.6rem;
+    font-size: 11px;
+  }
+  .admin-url-style-example code {
+    font-size: 11px;
+    color: var(--ink-2);
+    overflow-wrap: anywhere;
+  }
+  .admin-url-style-notes {
+    list-style: disc;
+    padding-left: 1.1rem;
+    display: flex;
+    flex-direction: column;
+    gap: 0.2rem;
+    color: var(--ink-3);
+  }
+
   @container settings-page (max-width: 1039px) {
     .admin-settings-work {
       grid-template-columns: minmax(0, 1fr);