refactor(vscode-ide-companion): 重构 WebViewProvider 初始化逻辑

- 抽离初始化代理连接逻辑到单独的方法中
- 优化面板恢复时的代理连接流程
- 移除 EmptyState 组件中的信息横幅
- 在 App 组件中添加可关闭的信息横幅
- 调整输入表单样式，移除冗余样式

packages/vscode-ide-companion/src/webview/App.tsx

@@ -66,6 +66,7 @@ export const App: React.FC = () => {
   );
   const messagesEndRef = useRef<HTMLDivElement>(null);
   const inputFieldRef = useRef<HTMLDivElement>(null);
+  const [showBanner, setShowBanner] = useState(true);
 
   const handlePermissionRequest = React.useCallback(
     (request: {
@@ -464,6 +465,55 @@ export const App: React.FC = () => {
         )}
       </div>
 
+      {/* Info Banner */}
+      {showBanner && (
+        <div className="info-banner">
+          <div className="banner-content">
+            <svg
+              className="banner-icon"
+              width="16"
+              height="16"
+              viewBox="0 0 20 20"
+              xmlns="http://www.w3.org/2000/svg"
+            >
+              <path d="M5.14648 7.14648C5.34175 6.95122 5.65825 6.95122 5.85352 7.14648L8.35352 9.64648C8.44728 9.74025 8.5 9.86739 8.5 10C8.5 10.0994 8.47037 10.1958 8.41602 10.2773L8.35352 10.3535L5.85352 12.8535C5.65825 13.0488 5.34175 13.0488 5.14648 12.8535C4.95122 12.6583 4.95122 12.3417 5.14648 12.1465L7.29297 10L5.14648 7.85352C4.95122 7.65825 4.95122 7.34175 5.14648 7.14648Z"></path>
+              <path d="M14.5 12C14.7761 12 15 12.2239 15 12.5C15 12.7761 14.7761 13 14.5 13H9.5C9.22386 13 9 12.7761 9 12.5C9 12.2239 9.22386 12 9.5 12H14.5Z"></path>
+              <path
+                fillRule="evenodd"
+                clipRule="evenodd"
+                d="M16.5 4C17.3284 4 18 4.67157 18 5.5V14.5C18 15.3284 17.3284 16 16.5 16H3.5C2.67157 16 2 15.3284 2 14.5V5.5C2 4.67157 2.67157 4 3.5 4H16.5ZM3.5 5C3.22386 5 3 5.22386 3 5.5V14.5C3 14.7761 3.22386 15 3.5 15H16.5C16.7761 15 17 14.7761 17 14.5V5.5C17 5.22386 16.7761 5 16.5 5H3.5Z"
+              ></path>
+            </svg>
+            <label>
+              Prefer the Terminal experience?{' '}
+              <a href="#" className="banner-link">
+                Switch back in Settings.
+              </a>
+            </label>
+          </div>
+          <button
+            className="banner-close"
+            aria-label="Close banner"
+            onClick={() => setShowBanner(false)}
+          >
+            <svg
+              width="10"
+              height="10"
+              viewBox="0 0 14 14"
+              fill="none"
+              xmlns="http://www.w3.org/2000/svg"
+            >
+              <path
+                d="M1 1L13 13M1 13L13 1"
+                stroke="currentColor"
+                strokeWidth="1.5"
+                strokeLinecap="round"
+              ></path>
+            </svg>
+          </button>
+        </div>
+      )}
+
       <div className="input-form-container">
         <div className="input-form-wrapper">
           <form className="input-form" onSubmit={handleSubmit}>