refactor(admin): 重构管理员设置模型渠道配置结构

- 将公开设置中的模型相关字段统一收拢到 modelChannel 配置组
- 更新 AdminPublicSettings 类型定义为 AdminPublicModelChannelSettings
- 在前端表单中调整模型配置字段路径到 public.modelChannel 下
- 更新设置规范化函数以适配新的嵌套配置结构
- 修改依赖注入和文档以反映配置结构变化
- 添加系统配置数据结构文档说明新的配置格式

web/src/app/layout.tsx

@@ -1,4 +1,6 @@
 import type { Metadata } from "next";
+import Script from "next/script";
+import { AntdRegistry } from "@ant-design/nextjs-registry";
 import { AppProviders } from "@/components/app-providers";
 import "antd/dist/reset.css";
 import "./globals.css";
@@ -22,12 +24,16 @@ export default function RootLayout({
             '"SF Pro Display","SF Pro Text","PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif',
         }}
       >
-        <script
+        <Script
+          id="theme-script"
+          strategy="beforeInteractive"
           dangerouslySetInnerHTML={{
             __html: `try{var s=JSON.parse(localStorage.getItem("infinite-canvas:theme_store")||"{}");var t=s.state&&s.state.theme==="light"?"light":"dark";document.documentElement.classList.toggle("dark",t==="dark");document.documentElement.style.colorScheme=t}catch(e){}`,
           }}
         />
-        <AppProviders>{children}</AppProviders>
+        <AntdRegistry>
+          <AppProviders>{children}</AppProviders>
+        </AntdRegistry>
       </body>
     </html>
   );