产品体验修复：P0 阻塞 + P1/P2 改善（产品审查 14 项中修复 10 项）

P0 阻塞：
- Pro 加载不再阻塞整个看板：只显示精简顶栏 + 加载状态，不再遮盖整个页面
- Scan 失败加重试按钮：所有用户（含免费）均可手动重试
- Detail Panel 同步超时后显示提示："同步时间较长，当前展示的数据可能不完整"

P1 体验：
- 登录页增加"忘记密码"链接：调用 Supabase 密码重置流程
- 登录失败/邮箱未验证增加明确提示："如刚注册，请先点击验证链接"
- 公告横幅增加 ✕ 关闭按钮：点击后永久隐藏

P2 改善：
- entitlement-required 页面重设计：品牌化、增加返回首页和登录按钮
- 订阅帮助页中英双语：所有 FAQ 和 UI 文案支持中英文切换
- 新增产品审查文档 docs/product-review-jun-2026.md

Tested: npx tsc --noEmit

frontend/app/entitlement-required/page.tsx

@@ -1,3 +1,5 @@
+import Link from "next/link";
+
 type Props = {
   searchParams?: Promise<{ next?: string }>;
 };
@@ -21,37 +23,82 @@ export default async function EntitlementRequiredPage({ searchParams }: Props) {
       <section
         style={{
           width: "100%",
-          maxWidth: 720,
+          maxWidth: 480,
           border: "1px solid rgba(68, 92, 140, 0.45)",
           borderRadius: 16,
           padding: 24,
           background: "rgba(9, 18, 36, 0.88)",
           boxShadow: "0 20px 50px rgba(0, 0, 0, 0.35)",
+          textAlign: "center",
         }}
       >
-        <h1 style={{ margin: 0, fontSize: 28, lineHeight: 1.2 }}>
-          Entitlement Required
+        <h1
+          style={{
+            margin: 0,
+            fontSize: 22,
+            lineHeight: 1.3,
+            fontWeight: 800,
+          }}
+        >
+          需要登录方可访问此页面
         </h1>
         <p style={{ marginTop: 12, color: "#9fb2da", lineHeight: 1.6 }}>
-          This dashboard is protected. If Supabase auth is enabled, please go to{" "}
-          <a
+          本页面需要登录权限。请登录后重试。
+          <br />
+          Sign in required to access this page.
+        </p>
+        <div style={{ marginTop: 20, display: "flex", gap: 12, justifyContent: "center", flexWrap: "wrap" }}>
+          <Link
             href={`/auth/login?next=${encodeURIComponent(nextPath)}`}
             style={{
-              color: "#8fc5ff",
               display: "inline-flex",
-              minHeight: 36,
               alignItems: "center",
+              gap: 6,
+              minHeight: 40,
+              padding: "8px 20px",
+              borderRadius: 12,
+              background: "linear-gradient(135deg, #2563EB, #4F46E5)",
+              color: "#fff",
+              fontWeight: 700,
+              textDecoration: "none",
+              fontSize: 14,
             }}
           >
-            /auth/login
-          </a>{" "}
-          to sign in first.
-        </p>
-        <p style={{ marginTop: 12, color: "#9fb2da", lineHeight: 1.6 }}>
-          Legacy mode still supports <code>?access_token=&lt;your-token&gt;</code>.
-        </p>
-        <p style={{ marginTop: 12, color: "#9fb2da", lineHeight: 1.6 }}>
-          Requested path: <code>{nextPath}</code>
+            去登录 / Sign in
+          </Link>
+          <Link
+            href="/"
+            style={{
+              display: "inline-flex",
+              alignItems: "center",
+              gap: 6,
+              minHeight: 40,
+              padding: "8px 20px",
+              borderRadius: 12,
+              border: "1px solid rgba(68, 92, 140, 0.45)",
+              background: "rgba(68, 92, 140, 0.2)",
+              color: "#d6e2ff",
+              fontWeight: 600,
+              textDecoration: "none",
+              fontSize: 14,
+            }}
+          >
+            返回首页 / Back to Home
+          </Link>
+        </div>
+        <p
+          style={{
+            marginTop: 20,
+            fontSize: 12,
+            color: "#7891b5",
+            lineHeight: 1.5,
+          }}
+        >
+          传统令牌模式仍支持 <code style={{ background: "rgba(255,255,255,0.06)", padding: "2px 6px", borderRadius: 4 }}>?access_token=&lt;your-token&gt;</code>
+          <br />
+          <span style={{ marginTop: 4, display: "inline-block" }}>
+            请求路径 / Requested path: <code>{nextPath}</code>
+          </span>
         </p>
       </section>
     </main>