feat: Vike 骨架（pages feed+spa / renderer 双端入口 / AppShell 拆分 / serverClient）

vite.config 接入 vike 插件并改产出 dist/client+dist/server；feed 白名单 route 匹配 /、/board/:id、/post/:id(.html)；spa catch-all ssr:false；onRenderHtml renderToReadableStream 等 allReady 输出完整 HTML 并带主题/缩放脚本；onRenderClient 沿用样式表等待+冷启动预热+hydrate 回退；getHomeStoreState 作用域 + hydrating 变体入 RequestScope；删除 index.html 与 main.tsx

frontend/renderer/+onRenderHtml.tsx

@@ -0,0 +1,65 @@
+import type { ComponentType, ReactElement } from 'react';
+import { renderToReadableStream } from 'react-dom/server';
+import { escapeInject, dangerouslySkipEscape } from 'vike/server';
+import type { PageContextServer } from 'vike/types';
+import App from '../src/App';
+import { createHomeStore } from '../src/store/homeStore';
+import { createRequestScope } from '../src/ssr/scopeTypes';
+import { runWithScope } from '../src/ssr/scope';
+
+export { onRenderHtml };
+
+type PageComponent = ComponentType<{ url?: string }>;
+
+/** 首帧主题脚本（localStorage j13-theme），与旧 index.html 保持一致 */
+const THEME_INIT_SCRIPT
+  = "(function(){var t=localStorage.getItem('j13-theme')||'light';document.documentElement.classList.toggle('dark',t==='dark');document.documentElement.style.colorScheme=t;})();";
+
+/** 锁死手机/平板双指与手势缩放；头像裁剪 / 图片灯箱放行 pinch */
+const ZOOM_BLOCK_SCRIPT
+  = "(function(){function inZoomAllowArea(target){return !!(target&&target.closest&&target.closest('.avatar-crop-stage, .image-lightbox'));}function blockGesture(e){if(inZoomAllowArea(e.target))return;if(e.cancelable)e.preventDefault();}function blockMultiTouch(e){if(e.touches&&e.touches.length>1){if(inZoomAllowArea(e.target))return;if(e.cancelable)e.preventDefault();}}document.addEventListener('gesturestart',blockGesture,{passive:false});document.addEventListener('gesturechange',blockGesture,{passive:false});document.addEventListener('gestureend',blockGesture,{passive:false});document.addEventListener('touchstart',blockMultiTouch,{passive:false});document.addEventListener('touchmove',blockMultiTouch,{passive:false});})();";
+
+/** 等 lazy 页面全部渲染完成（allReady）后缓冲为完整 HTML，首字节语义与旧 Go 文档级 SSR 一致 */
+async function renderPageToString(element: ReactElement): Promise<string> {
+  const stream = await renderToReadableStream(element, {
+    onError(err) {
+      console.error('[j13] SSR 渲染错误:', err);
+    },
+  });
+  await stream.allReady;
+  return new Response(stream).text();
+}
+
+async function onRenderHtml(pageContext: PageContextServer) {
+  const Page = pageContext.Page as PageComponent | undefined;
+
+  let pageHtml = '';
+  if (Page) {
+    // SSR feed 页：per-request 作用域 + hydrate 同构变体；渲染失败降级空壳（客户端自行接管），不 500
+    const scope = createRequestScope(createHomeStore());
+    scope.hydrating = true;
+    const { pathname, searchOriginal } = pageContext.urlParsed;
+    const url = pathname + (searchOriginal ?? '');
+    try {
+      pageHtml = await runWithScope(scope, () => renderPageToString(<Page url={url} />));
+    } catch (err) {
+      console.error('[j13] SSR 渲染失败，降级 SPA 壳:', err);
+      pageHtml = '';
+    }
+  }
+
+  return escapeInject`<!DOCTYPE html>
+<html lang="zh-CN">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
+    <meta name="description" content="拾三一隅，自在交流" />
+    <title>姜十三论坛 - 拾三一隅，自在交流</title>
+    <script>${dangerouslySkipEscape(THEME_INIT_SCRIPT)}</script>
+    <script>${dangerouslySkipEscape(ZOOM_BLOCK_SCRIPT)}</script>
+  </head>
+  <body>
+    <div id="root">${dangerouslySkipEscape(pageHtml)}</div>
+  </body>
+</html>`;
+}