perf(代码执行): 优化 Pyodide 引擎加载机制

- 升级 Pyodide 版本从 v0.24.1 到 v0.27.0
- 添加多 CDN 备用机制，提高加载成功率
- 加载失败时自动切换到备用 CDN
- 改进加载进度提示和错误处理

src/lib/code-runner/engines/pyodide.ts

@@ -28,14 +28,18 @@ const EXECUTION_TIMEOUT = 30000;
 // 最大输出长度
 const MAX_OUTPUT_LENGTH = 50000;
 
-// Pyodide CDN URL
+// Pyodide CDN URLs（按优先级排序）
-const PYODIDE_CDN = 'https://cdn.jsdelivr.net/pyodide/v0.24.1/full/';
+const PYODIDE_CDN_LIST = [
+  'https://cdn.jsdelivr.net/pyodide/v0.27.0/full/',  // jsDelivr CDN
+  'https://cdn.jsdelivr.net/npm/pyodide@0.27.0/',    // npm CDN 备用
+];
 
 class PyodideEngine implements IExecutionEngine {
   private pyodide: PyodideInterface | null = null;
   private loading = false;
   private loadPromise: Promise<PyodideInterface> | null = null;
   private loadingCallbacks: PyodideLoadingCallback | null = null;
+  private currentCdnIndex = 0;
 
   supports(language: string): boolean {
     const lang = language.toLowerCase();
@@ -120,11 +124,30 @@ class PyodideEngine implements IExecutionEngine {
     this.loadingCallbacks?.onLoadingProgress?.('正在加载 Python 运行时...', 0);
 
     this.loadPromise = new Promise<PyodideInterface>(async (resolve, reject) => {
+      let lastError: Error | null = null;
+
+      // 尝试所有 CDN
+      for (let i = 0; i < PYODIDE_CDN_LIST.length; i++) {
+        const cdnUrl = PYODIDE_CDN_LIST[i];
+        this.currentCdnIndex = i;
+
         try {
           // 动态加载 Pyodide 脚本
-        if (typeof window !== 'undefined' && !(window as unknown as Record<string, unknown>).loadPyodide) {
+          if (typeof window !== 'undefined') {
-          this.loadingCallbacks?.onLoadingProgress?.('正在下载 Pyodide...', 20);
+            // 移除之前可能加载失败的脚本
-          await this.loadScript(`${PYODIDE_CDN}pyodide.js`);
+            const existingScript = document.querySelector('script[data-pyodide]');
+            if (existingScript) {
+              existingScript.remove();
+            }
+
+            // 重置 loadPyodide 函数
+            delete (window as unknown as Record<string, unknown>).loadPyodide;
+
+            this.loadingCallbacks?.onLoadingProgress?.(
+              `正在下载 Pyodide (CDN ${i + 1}/${PYODIDE_CDN_LIST.length})...`,
+              20
+            );
+            await this.loadScript(`${cdnUrl}pyodide.js`);
           }
 
           this.loadingCallbacks?.onLoadingProgress?.('正在初始化 Python 环境...', 50);
@@ -132,8 +155,12 @@ class PyodideEngine implements IExecutionEngine {
           // 初始化 Pyodide
           const loadPyodide = (window as unknown as { loadPyodide: (config: { indexURL: string }) => Promise<PyodideInterface> }).loadPyodide;
 
+          if (!loadPyodide) {
+            throw new Error('loadPyodide 函数未加载');
+          }
+
           const pyodide = await loadPyodide({
-          indexURL: PYODIDE_CDN,
+            indexURL: cdnUrl,
           });
 
           this.loadingCallbacks?.onLoadingProgress?.('Python 环境准备就绪', 100);
@@ -170,13 +197,27 @@ sys.stderr = __output_capture__
           this.loadingCallbacks?.onLoadingComplete?.();
 
           resolve(pyodide);
+          return; // 成功加载，退出循环
         } catch (error) {
+          lastError = error instanceof Error ? error : new Error(String(error));
+          console.warn(`Pyodide CDN ${i + 1} 加载失败:`, lastError.message);
+
+          // 如果还有其他 CDN，继续尝试
+          if (i < PYODIDE_CDN_LIST.length - 1) {
+            this.loadingCallbacks?.onLoadingProgress?.(
+              `CDN ${i + 1} 加载失败，尝试备用 CDN...`,
+              10
+            );
+          }
+        }
+      }
+
+      // 所有 CDN 都失败了
       this.loading = false;
       this.loadPromise = null;
-        const errorMsg = error instanceof Error ? error.message : String(error);
+      const errorMsg = lastError?.message || '未知错误';
       this.loadingCallbacks?.onLoadingError?.(errorMsg);
       reject(new Error(`Pyodide 加载失败: ${errorMsg}`));
-      }
     });
 
     return this.loadPromise;
@@ -186,6 +227,7 @@ sys.stderr = __output_capture__
     return new Promise((resolve, reject) => {
       const script = document.createElement('script');
       script.src = src;
+      script.setAttribute('data-pyodide', 'true');
       script.onload = () => resolve();
       script.onerror = () => reject(new Error(`Failed to load script: ${src}`));
       document.head.appendChild(script);