feat: 前端HESUPIPE品牌化+管道文案+GDPR提示

- 品牌色橙#f08a31→HESUPIPE蓝#066fc0(取自官网主题CSS a:hover/导航主色),7槽位色板三处同步:theme.js/widget.js内联副本/style.css :root
- chat.html/widget.js/js/chat.js:标题HESUPIPE Support、管道场景描述、欢迎语、热门话题Get Quotation/Pipe Specifications/Delivery & Shipping、WhatsApp+8615937108317、邮箱hesu@hesuu.com
- 邀请卡文案管道化(pipe specs, MOQ, delivery timing)+GDPR小字;聊天面板footer GDPR行(复用.chat-footer)
- admin.html VOLT→HESUPIPE;头像PIL重绘为品牌蓝底白H(512/128px)
- widget-test.html色值同步+断言基准更新(浏览器断言9/9 Δ=0);.gitignore排除.playwright-mcp/

Co-Authored-By: Claude Code <noreply@anthropic.com>

static/js/chat.js

@@ -29,8 +29,8 @@
 (function () {
     // 联系方式配置（与 widget.js 的 data-* 机制一致）
     var chatScript = document.currentScript || document.querySelector('script[src*="chat.js"]');
-    var whatsapp = (chatScript && chatScript.getAttribute("data-whatsapp")) || "https://wa.me/+8619037179250";
-    var email = (chatScript && chatScript.getAttribute("data-email")) || "mailto:info@borderlesscar.com";
+    var whatsapp = (chatScript && chatScript.getAttribute("data-whatsapp")) || "https://wa.me/+8615937108317";
+    var email = (chatScript && chatScript.getAttribute("data-email")) || "mailto:hesu@hesuu.com";
     var waBtn = document.querySelector('.whatsapp-btn');
     var emBtn = document.querySelector('.email-btn');
     if (waBtn) waBtn.href = whatsapp;