docs: 公开页提速设计方案（压缩A′ + 公开页去Flutter化）+ 登记索引

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JJ1g8XV1YhhmHRzhwWEW7o

docs/index.html

@@ -38,6 +38,7 @@
   <h2>🏗 设计方案</h2>
   <ul>
     <li><a href="pay支付对接开发指南.html">pay 支付对接开发指南</a><span class="tag html">HTML</span> <span class="hint">— jiu 门店应用内购买/续费授权：付款走 pay，付成功后 pay 签名 webhook 回调 jiu 直接续期。含签名算法、下单/回调接口契约、套餐 biz_code→权益映射、续期逻辑、安全红线、客户端(Web+App webview)、联调清单。pay 侧已就绪，本文档=jiu 侧要实现的部分</span></li>
+    <li><a href="design/public-page-speedup.html">公开页提速方案（传输压缩 + 公开页全面去 Flutter 化）</a><span class="tag html">HTML</span> <span class="hint">— 扫码首开 30s 根因与两级修复：CI 预压缩+gzip_static+协商缓存 / 商品页+店铺列表页后端 SSR，公开动线零 Flutter（2026-07-07）</span></li>
     <li><a href="design/order-return-prototype.html">退单原型（已审核单据）</a><span class="tag html">HTML</span></li>
     <li><a href="design/order-print-layouts.html">出入库单打印排版方案（6 种黑白样式精选）</a><span class="tag html">HTML</span> · <a href="design/order-print-layouts.pdf">PDF</a></li>
     <li><a href="design/stock-in-cost-confirm-design.html">入库确认进价（暂估价前向补偿）设计</a><span class="tag html">HTML</span></li>