feat(ui): 优化 Chat 页面 Header 布局

- 移除左上角 "Chat" 标题
- Token 使用情况移至左侧
- 压缩按钮添加文字标签，更直观
- 工具栏按钮保持在右侧

packages/ui/src/components/ContextUsage.tsx

@@ -158,19 +158,25 @@ export function ContextUsage({
             variant="ghost"
             size="sm"
             className={cn(
-              'h-5 px-1.5 text-xs',
+              'h-5 px-1.5 text-xs gap-1',
               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"
+            title="压缩对话上下文以释放 token 空间"
           >
             {compressing ? (
+              <>
                 <RefreshCw size={12} className="animate-spin" />
+                <span>压缩中</span>
+              </>
             ) : (
+              <>
                 <Zap size={12} />
+                <span>压缩</span>
+              </>
             )}
           </Button>
         )}

packages/web/src/pages/Chat.tsx

@@ -134,9 +134,8 @@ export function ChatPage({
     <div className="flex-1 flex flex-col h-full">
       {/* Header */}
       <div className="flex items-center justify-between px-4 md:px-6 py-3 border-b border-line bg-surface-subtle">
-        <h1 className="text-lg font-medium text-fg">Chat</h1>
+        {/* 左侧：上下文使用情况 */}
-        <div className="flex items-center gap-3 flex-shrink-0">
+        <div className="flex items-center">
-          {/* 上下文使用情况 - 紧凑模式 */}
           {sessionId && (
             <ContextUsage
               sessionId={sessionId}
@@ -145,10 +144,11 @@ export function ChatPage({
               refreshInterval={30000}
             />
           )}
+        </div>
 
-          {/* 工具栏按钮 */}
+        {/* 右侧：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">
+          <div className="flex items-center gap-1.5 flex-shrink-0">
             {/* LSP 诊断指示器 */}
             {(onOpenLSP || onOpenDiagnostics) && (
               <DiagnosticsIndicator
@@ -185,7 +185,6 @@ export function ChatPage({
           </div>
         )}
       </div>
-      </div>
 
       {/* Messages */}
       <div className="flex-1 overflow-y-auto p-6">