fix(web): 首頁 Tab 切換同步修正 — activeTabId 追蹤 URL query 變化

apps/web/src/app/[locale]/page.tsx

@@ -733,9 +733,20 @@ export default function Home({ params }: { params: { locale: string } }) {
     { id: 'disposition', label: '處置統計', content: <DispositionTab /> },
   ]
 
-  // 判斷目前 Tab
-  const searchParams = typeof window !== 'undefined' ? new URLSearchParams(window.location.search) : null
-  const currentTab = searchParams?.get('tab') || 'overview'
+  // Sprint 5: 從 URL 讀取當前 Tab
+  const [activeTabId, setActiveTabId] = useState('overview')
+
+  // 每 100ms 檢查 URL query 變化（PageTabs 用 router.push 更新）
+  useEffect(() => {
+    const check = () => {
+      const params = new URLSearchParams(window.location.search)
+      const tab = params.get('tab') || 'overview'
+      setActiveTabId(prev => prev !== tab ? tab : prev)
+    }
+    check()
+    const interval = setInterval(check, 100)
+    return () => clearInterval(interval)
+  }, [])
 
   return (
     <AppLayout locale={locale} showBackground={false} fullBleed>
@@ -746,8 +757,8 @@ export default function Home({ params }: { params: { locale: string } }) {
         syncWithUrl={true}
       />
 
-      {/* Tab 1 戰情總覽: 顯示現有首頁完整內容 (不動任何東西) */}
-      {(currentTab === 'overview' || !currentTab) && (
+      {/* Tab 1 戰情總覽: 顯示現有首頁完整內容 */}
+      {activeTabId === 'overview' && (
       <div style={{
         display: 'flex',
         flexDirection: 'column',