refactor(basic): 优化主窗口获取逻辑

- 将判断错误码的条件从 if (errCode) 修改为 if (errCode !== 0)
- 这样可以更准确地处理错误情况，避免潜在的逻辑错误

src/main/ets/ContextConfig.ets

@@ -21,7 +21,7 @@ export class GlobalContext {
 
     context.windowStage.getMainWindow((err: BusinessError, data) => {
       let errCode: number = err.code;
-      if (errCode) {
+      if (errCode !== 0) {
         console.error(`Failed to obtain the main window. Cause code: ${err.code}, message: ${err.message}`);
         return;
       }