chore(analytics): CR - 修 x-satoken header / storage try/catch / timer 清理等

Copilot CR #277:
- lib/analytics: 客户端 → Next /api/analytics 用 x-satoken（之前用 satoken 导致 resolveUserId 解析不到 userId，uniqueUsers 恒为 0）
- lib/analytics: localStorage 读取用 try/catch，Safari 隐私模式不崩
- lib/analytics: headers 用 Record<string,string> 而不是 HeadersInit 联合类型，可变安全
- DocsPageViewTracker: sessionStorage 读写 try/catch 降级到内存去重
- DocShareButton: useRef 存 setTimeout id，unmount 时 clearTimeout；加 type='button' 避免 form 内误触发提交
- CustomSearchDialog: 注释修正（'搜索结果点击' → '搜索词输入'）

Author: longsizhuo

app/components/CustomSearchDialog.tsx

@@ -92,7 +92,7 @@ export function CustomSearchDialog({
     if (!search) return;
 
     const timer = setTimeout(() => {
-      // Umami 埋点: 搜索结果点击
+      // Umami 埋点: 搜索词输入（debounce 1s，非搜索结果点击）
       if (window.umami) {
         window.umami.track("search_query", { query: search });
       }

app/components/DocShareButton.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import { trackEvent } from "@/lib/analytics";
 
 /**
@@ -9,14 +9,23 @@ import { trackEvent } from "@/lib/analytics";
  */
 export function DocShareButton() {
   const [copied, setCopied] = useState(false);
+  // timer ref：每次新点击 / 组件卸载时清掉旧 timer，避免 setState on unmounted
+  const resetTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    return () => {
+      if (resetTimerRef.current) clearTimeout(resetTimerRef.current);
+    };
+  }, []);
 
   const handleCopy = async () => {
     const url = window.location.href;
     try {
       await navigator.clipboard.writeText(url);
       setCopied(true);
-      // 2s 后恢复按钮文案
-      setTimeout(() => setCopied(false), 2000);
+      // 旧 timer 先清掉，避免连点两次后提前恢复文案
+      if (resetTimerRef.current) clearTimeout(resetTimerRef.current);
+      resetTimerRef.current = setTimeout(() => setCopied(false), 2000);
     } catch {
       // clipboard 不可用时静默失败
     }
@@ -27,6 +36,7 @@ export function DocShareButton() {
 
   return (
     <button
+      type="button"
       onClick={handleCopy}
       className="inline-flex items-center gap-2 rounded-md px-4 h-11 text-base font-medium hover:bg-muted/80 hover:text-foreground"
       aria-label="复制页面链接"

app/components/DocsPageViewTracker.tsx

@@ -18,13 +18,22 @@ export function DocsPageViewTracker() {
     if (!pathname) return;
 
     const dedupeKey = `pv:${pathname}`;
-    // sessionStorage 去重：同一 session 内同一路径不重复上报
-    if (sessionStorage.getItem(dedupeKey)) return;
+    // sessionStorage 可能因为存储禁用 / 配额超限 / Safari 隐私模式抛错；
+    // 埋点的去重不能因此报错破坏导航，用 try/catch 降级到内存去重
+    try {
+      if (sessionStorage.getItem(dedupeKey)) return;
+    } catch {
+      // 读失败时跳过 session 去重，后面的内存去重仍然生效
+    }
     // 内存去重：防止 React StrictMode 双重 effect 重复调用
     if (lastTrackedRef.current === pathname) return;
 
     lastTrackedRef.current = pathname;
-    sessionStorage.setItem(dedupeKey, "1");
+    try {
+      sessionStorage.setItem(dedupeKey, "1");
+    } catch {
+      // 写失败时下一个 session / 刷新会再报一次，可接受
+    }
 
     trackEvent("page_view", {
       path: pathname,