feat(frontend): add management portal landing page

frontend/site/src/App.jsx

@@ -0,0 +1,100 @@
+import {
+  ArrowRight,
+  ArrowSquareOut,
+  ShieldCheck,
+} from "@phosphor-icons/react";
+
+const portals = [
+  {
+    number: "01",
+    title: "平台总后台",
+    description: "全局治理 · 安全运营 · 数据协同",
+    href: "http://p.heqiapp.com",
+    tone: "platform",
+  },
+  {
+    number: "02",
+    title: "气站管理后台",
+    description: "站点经营 · 履约管理 · 安全服务",
+    href: "http://z.heqiapp.com",
+    tone: "station",
+  },
+  {
+    number: "03",
+    title: "配送点管理后台",
+    description: "智能调度 · 高效配送 · 全程可追溯",
+    href: "http://d.heqiapp.com",
+    tone: "delivery",
+  },
+];
+
+function PortalLink({ portal }) {
+  return (
+    <a
+      className={`portal portal--${portal.tone}`}
+      href={portal.href}
+      target="_blank"
+      rel="noreferrer"
+      aria-label={`进入${portal.title}，将在新标签页打开`}
+    >
+      <div className="portal__heading">
+        <span className="portal__number" aria-hidden="true">
+          {portal.number}
+        </span>
+        <span className="portal__divider" aria-hidden="true" />
+        <div>
+          <h2>{portal.title}</h2>
+          <p>{portal.description}</p>
+        </div>
+      </div>
+      <span className="portal__action">
+        进入系统
+        <ArrowRight size={22} weight="bold" aria-hidden="true" />
+      </span>
+    </a>
+  );
+}
+
+export function App() {
+  return (
+    <main className="site-shell">
+      <img
+        className="ecosystem-scene"
+        src="/assets/heqi-ecosystem-hero.jpg"
+        alt=""
+        aria-hidden="true"
+      />
+
+      <header className="site-header">
+        <a className="brand" href="/" aria-label="和气首页">
+          <img src="/assets/heqi-logo.svg" alt="" />
+          <span>和气</span>
+        </a>
+        <div className="trust-line">
+          <ShieldCheck size={20} weight="regular" aria-hidden="true" />
+          <span>安全可靠 · 稳定高效 · 智能互联</span>
+        </div>
+      </header>
+
+      <section className="hero" aria-labelledby="hero-title">
+        <p className="hero__eyebrow">HEQI SMART GAS PLATFORM</p>
+        <h1 id="hero-title">安全连接每一程</h1>
+        <p className="hero__description">
+          <span>智能瓶阀、气站运营与配送履约</span>
+          <span>的一体化管理入口</span>
+        </p>
+      </section>
+
+      <nav className="portal-grid" aria-label="管理系统入口">
+        {portals.map((portal) => (
+          <PortalLink key={portal.href} portal={portal} />
+        ))}
+      </nav>
+
+      <p className="external-note">
+        <ArrowSquareOut size={17} weight="regular" aria-hidden="true" />
+        系统将在新标签页中打开
+      </p>
+    </main>
+  );
+}