feat: 集成 VSCode Authentication API 实现用户登录

- 新增 Authentication Provider，登录信息显示在左下角
- 支持浏览器登录并自动回调
- 登录/登出后自动刷新窗口
- 侧边栏根据登录状态显示不同按钮

src/views/ICViewProvider.ts

@@ -103,7 +103,23 @@ export function showICHelperPanel(context: vscode.ExtensionContext) {
  * 侧边栏视图提供者
  */
 export class ICViewProvider implements vscode.WebviewViewProvider {
-  constructor(private readonly extensionUri: vscode.Uri) {}
+  constructor(
+    private readonly extensionUri: vscode.Uri,
+    private readonly context: vscode.ExtensionContext
+  ) {}
+
+  /**
+   * 检查登录状态（使用 Authentication API）
+   */
+  private async checkLoginStatus(): Promise<boolean> {
+    try {
+      const session = await vscode.authentication.getSession("iccoder", [], { createIfNone: false });
+      return !!session;
+    } catch (error) {
+      console.log("检查登录状态失败:", error);
+      return false;
+    }
+  }
 
   resolveWebviewView(webviewView: vscode.WebviewView) {
     webviewView.webview.options = {
@@ -111,17 +127,28 @@ export class ICViewProvider implements vscode.WebviewViewProvider {
       localResourceRoots: [vscode.Uri.joinPath(this.extensionUri, "media")],
     };
 
-    webviewView.webview.html = this.getWebviewContent(webviewView.webview);
+    // 检查是否已登录（使用 Authentication API）
+    this.checkLoginStatus().then((isLoggedIn) => {
+      webviewView.webview.html = this.getWebviewContent(
+        webviewView.webview,
+        isLoggedIn
+      );
+    });
 
     // 处理侧边栏的消息
     webviewView.webview.onDidReceiveMessage((message) => {
       if (message.command === "openChat") {
         vscode.commands.executeCommand("ic-coder.openChat");
+      } else if (message.command === "login") {
+        vscode.commands.executeCommand("ic-coder.login");
       }
     });
   }
 
-  private getWebviewContent(webview: vscode.Webview): string {
+  private getWebviewContent(
+    webview: vscode.Webview,
+    isLoggedIn: boolean
+  ): string {
     const logoUri = webview.asWebviewUri(
       vscode.Uri.joinPath(this.extensionUri, "media", "icon.png")
     );
@@ -184,7 +211,11 @@ export class ICViewProvider implements vscode.WebviewViewProvider {
         <div class="container">
           <img src="${logoUri}" alt="IC Coder" width="120" />
           <h2>欢迎使用 IC Coder</h2>
-          <button class="btn" onclick="openChat()">开始创作</button>
+          ${
+            isLoggedIn
+              ? '<button class="btn" onclick="openChat()">开始创作</button>'
+              : '<button class="btn" onclick="login()">登录账户</button>'
+          }
         </div>
 
         <script>
@@ -194,6 +225,11 @@ export class ICViewProvider implements vscode.WebviewViewProvider {
             vscode.postMessage({ command: 'openChat' });
           }
 
+          // 登录功能
+          function login() {
+            vscode.postMessage({ command: 'login' });
+          }
+
           function generateCode(type) {
             const code = getCodeTemplate(type);
             vscode.postMessage({