style(界面): 优化设置页面和 API Key 配置提示

- 聊天页面添加 API Key 未配置提示卡片
- 移除设置页面的 CCH URL 配置项（使用默认值）
- 简化保存配置逻辑

src/app/chat/[id]/page.tsx

@@ -2,7 +2,8 @@
 
 import { useState, useRef, useEffect, use } from 'react';
 import { useRouter, useSearchParams } from 'next/navigation';
-import { Share2, MoreHorizontal, Loader2, Square, Clock, ChevronDown, Pencil, Trash2, Check, X } from 'lucide-react';
+import Link from 'next/link';
+import { Share2, MoreHorizontal, Loader2, Square, Clock, ChevronDown, Pencil, Trash2, Check, X, AlertTriangle, Settings } from 'lucide-react';
 import { Sidebar, SidebarToggle } from '@/components/layout/Sidebar';
 import { ChatInput } from '@/components/features/ChatInput';
 import { MessageBubble } from '@/components/features/MessageBubble';
@@ -448,6 +449,30 @@ export default function ChatPage({ params }: PageProps) {
         {/* 消息列表区域 */}
         <div className="flex-1 overflow-y-auto">
           <div className="max-w-[900px] mx-auto px-4 py-6">
+            {/* API Key 未配置提示 */}
+            {!settings?.cchApiKeyConfigured && (
+              <div className="mb-6 p-4 bg-amber-50 dark:bg-amber-900/20 border border-amber-200 dark:border-amber-800 rounded-lg">
+                <div className="flex items-start gap-3">
+                  <AlertTriangle className="w-5 h-5 text-amber-500 mt-0.5 flex-shrink-0" />
+                  <div className="flex-1">
+                    <h3 className="text-sm font-medium text-amber-800 dark:text-amber-200 mb-1">
+                      请先配置 API Key
+                    </h3>
+                    <p className="text-sm text-amber-700 dark:text-amber-300 mb-3">
+                      您需要配置自己的 API Key 才能使用 AI 对话功能。请前往设置页面完成配置。
+                    </p>
+                    <Link
+                      href="/settings"
+                      className="inline-flex items-center gap-2 px-4 py-2 bg-amber-500 hover:bg-amber-600 text-white text-sm font-medium rounded-lg transition-colors"
+                    >
+                      <Settings size={16} />
+                      前往设置
+                    </Link>
+                  </div>
+                </div>
+              </div>
+            )}
+
             {messages.length === 0 ? (
               <div className="flex flex-col items-center justify-center py-20 text-center">
                 <h2 className="text-xl font-medium text-[var(--color-text-primary)] mb-2">

src/app/settings/page.tsx

@@ -50,7 +50,6 @@ export default function SettingsPage() {
   const { tools, loading: toolsLoading } = useTools();
 
   // CCH 配置状态
-  const [cchUrl, setCchUrl] = useState('');
   const [cchApiKey, setCchApiKey] = useState('');
   const [showApiKey, setShowApiKey] = useState(false);
   const [saveStatus, setSaveStatus] = useState<'idle' | 'saving' | 'saved' | 'error'>('idle');
@@ -69,7 +68,6 @@ export default function SettingsPage() {
   // 当设置加载完成后，更新本地状态
   useEffect(() => {
     if (settings) {
-      setCchUrl(settings.cchUrl || '');
       setSystemPrompt(settings.systemPrompt || '');
       setTemperature(settings.temperature || '0.7');
     }
@@ -79,11 +77,9 @@ export default function SettingsPage() {
   const handleSaveCchConfig = async () => {
     setSaveStatus('saving');
     try {
-      const updates: Record<string, string> = { cchUrl };
       if (cchApiKey) {
-        updates.cchApiKey = cchApiKey;
+        await updateSettings({ cchApiKey });
       }
-      await updateSettings(updates);
       setSaveStatus('saved');
       setCchApiKey(''); // 清除输入的 API Key
       setTimeout(() => setSaveStatus('idle'), 2000);
@@ -317,19 +313,6 @@ export default function SettingsPage() {
           title="CCH 服务配置"
           description="配置 Claude Code Hub 服务连接"
         >
-              <SettingsItem
-                label="CCH 服务地址"
-                description="Claude Code Hub 服务的 URL"
-              >
-                <input
-                  type="text"
-                  className="settings-input w-80"
-                  value={cchUrl}
-                  onChange={(e) => setCchUrl(e.target.value)}
-                  placeholder="http://localhost:13500"
-                />
-              </SettingsItem>
-
               <SettingsItem
                 label="API Key"
                 description={