feat(ui): 优化 Header 和状态栏布局

- ContextUsage: 紧凑模式下始终显示压缩按钮
- StatusBar: 连接状态移至中间位置，显示绿点动画和文字
- StatusBar: 添加内部连接状态检测（通过 health API）
- Chat: 移除 Header 中的连接状态指示器

packages/ui/src/components/ContextUsage.tsx

@@ -152,9 +152,27 @@ export function ContextUsage({
         </div>
         {/* 数值 */}
         <span className={cn('text-xs', textColor)}>{formatted}</span>
-        {/* 警告图标 */}
-        {shouldCompress && (
-          <AlertTriangle size={12} className="text-amber-500" />
+        {/* 压缩按钮 */}
+        {showCompressButton && (
+          <Button
+            variant="ghost"
+            size="sm"
+            className={cn(
+              'h-5 px-1.5 text-xs',
+              shouldCompress
+                ? 'text-amber-500 hover:text-amber-400 hover:bg-amber-500/10'
+                : 'text-fg-muted hover:text-fg-secondary hover:bg-surface-muted'
+            )}
+            onClick={handleCompress}
+            disabled={compressing}
+            title="压缩对话上下文"
+          >
+            {compressing ? (
+              <RefreshCw size={12} className="animate-spin" />
+            ) : (
+              <Zap size={12} />
+            )}
+          </Button>
         )}
       </div>
     );

packages/ui/src/components/StatusBar.tsx

@@ -5,9 +5,9 @@
  */
 
 import { useState, useEffect, useCallback } from 'react';
-import { GitBranch, AlertTriangle, AlertCircle, Wifi, WifiOff, RefreshCw, CheckCircle } from 'lucide-react';
+import { GitBranch, AlertTriangle, AlertCircle, WifiOff, RefreshCw, CheckCircle } from 'lucide-react';
 import { cn } from '../utils/cn.js';
-import { getLSPDiagnostics, getGitInfo, type DiagnosticsSummary, type GitInfo } from '../api/client.js';
+import { getLSPDiagnostics, getGitInfo, getHealth, type DiagnosticsSummary, type GitInfo } from '../api/client.js';
 
 interface StatusBarProps {
   className?: string;
@@ -21,13 +21,17 @@ interface StatusBarProps {
 
 export function StatusBar({
   className,
-  isConnected = true,
+  isConnected: isConnectedProp,
   onDiagnosticsClick,
   refreshInterval = 30000,
 }: StatusBarProps) {
   const [diagnostics, setDiagnostics] = useState<DiagnosticsSummary | null>(null);
   const [gitInfo, setGitInfo] = useState<GitInfo | null>(null);
   const [loading, setLoading] = useState(false);
+  const [connectionStatus, setConnectionStatus] = useState(true);
+
+  // 如果外部传入了 isConnected，使用外部值；否则使用内部检测
+  const isConnected = isConnectedProp ?? connectionStatus;
 
   // 加载诊断信息和 Git 信息
   const loadData = useCallback(async () => {
@@ -45,12 +49,37 @@ export function StatusBar({
       if (gitResult.success && gitResult.data) {
         setGitInfo(gitResult.data);
       }
+
+      // 如果没有外部传入连接状态，内部检测
+      if (isConnectedProp === undefined) {
+        setConnectionStatus(true);
+      }
     } catch {
-      // 忽略错误
+      // 请求失败说明可能断开连接
+      if (isConnectedProp === undefined) {
+        setConnectionStatus(false);
+      }
     } finally {
       setLoading(false);
     }
-  }, []);
+  }, [isConnectedProp]);
+
+  // 检测连接状态（如果没有外部传入）
+  const checkConnection = useCallback(async () => {
+    if (isConnectedProp !== undefined) return;
+
+    try {
+      await getHealth();
+      setConnectionStatus(true);
+    } catch {
+      setConnectionStatus(false);
+    }
+  }, [isConnectedProp]);
+
+  // 初始连接检测
+  useEffect(() => {
+    checkConnection();
+  }, [checkConnection]);
 
   // 初始加载和定时刷新
   useEffect(() => {
@@ -94,6 +123,30 @@ export function StatusBar({
         </button>
       </div>
 
+      {/* 中间 - 连接状态 */}
+      <div
+        className={cn(
+          'flex items-center gap-1.5',
+          isConnected ? 'text-green-400' : 'text-red-400'
+        )}
+        title={isConnected ? 'Connected to server' : 'Disconnected from server'}
+      >
+        {isConnected ? (
+          <>
+            <span className="relative flex h-2 w-2">
+              <span className="animate-ping absolute inline-flex h-full w-full rounded-full bg-green-400 opacity-75" />
+              <span className="relative inline-flex rounded-full h-2 w-2 bg-green-500" />
+            </span>
+            <span>Connected</span>
+          </>
+        ) : (
+          <>
+            <WifiOff size={12} />
+            <span>Disconnected</span>
+          </>
+        )}
+      </div>
+
       {/* 右侧 */}
       <div className="flex items-center gap-3">
         {/* 诊断信息 */}
@@ -123,17 +176,6 @@ export function StatusBar({
             </span>
           )}
         </button>
-
-        {/* 连接状态 */}
-        <div
-          className={cn(
-            'flex items-center gap-1',
-            isConnected ? 'text-green-400' : 'text-red-400'
-          )}
-          title={isConnected ? 'Connected to server' : 'Disconnected from server'}
-        >
-          {isConnected ? <Wifi size={12} /> : <WifiOff size={12} />}
-        </div>
       </div>
     </div>
   );

packages/web/src/pages/Chat.tsx

@@ -3,7 +3,7 @@
  */
 
 import { useEffect, useRef } from 'react';
-import { WifiOff, MessageSquare, Terminal, Plug, Zap, Bot, History, Server, MessagesSquare } from 'lucide-react';
+import { MessageSquare, Terminal, Plug, Zap, Bot, History, Server, MessagesSquare } from 'lucide-react';
 import { motion, AnimatePresence } from 'framer-motion';
 import { toast } from 'sonner';
 import {
@@ -129,30 +129,6 @@ export function ChatPage({
     </motion.div>
   );
 
-  // 连接状态指示器
-  const ConnectionStatus = () => (
-    <div className="flex items-center gap-1.5 text-sm">
-      {isConnected ? (
-        <motion.div
-          initial={{ opacity: 0 }}
-          animate={{ opacity: 1 }}
-          className="flex items-center gap-1.5"
-        >
-          <span className="relative flex h-2.5 w-2.5">
-            <span className="animate-ping absolute inline-flex h-full w-full rounded-full bg-green-400 opacity-75" />
-            <span className="relative inline-flex rounded-full h-2.5 w-2.5 bg-green-500" />
-          </span>
-          <span className="text-green-400 hidden sm:inline">Connected</span>
-        </motion.div>
-      ) : (
-        <div className="flex items-center gap-1.5 text-red-400">
-          <WifiOff size={16} />
-          <span className="hidden sm:inline">Disconnected</span>
-        </div>
-      )}
-    </div>
-  );
-
   return (
     <div className="flex-1 flex flex-col h-full">
       {/* Header */}
@@ -164,14 +140,11 @@ export function ChatPage({
             <ContextUsage
               sessionId={sessionId}
               compact
-              showCompressButton={false}
+              showCompressButton
               refreshInterval={30000}
             />
           )}
 
-          {/* 连接状态 */}
-          <ConnectionStatus />
-
           {/* 工具栏按钮 */}
           {(onOpenCommands || onOpenMCP || onOpenHooks || onOpenAgents || onOpenCheckpoints || onOpenProviders || onOpenLSP || onOpenDiagnostics || onOpenSessions) && (
             <div className="flex items-center gap-1.5 border-l border-line-muted pl-3">