test(commands): 添加dry-run参数测试支持文件检测

- 增加--dry-run参数的测试用例
- 验证在dry-run模式下无支持文件的退出码和错误信息
- 确保无支持文件时正确返回错误码2

Author: clark-fc

packages/commands/tests/e2e/knowledge/knowledge-doc-upload.e2e.test.ts

@@ -191,6 +191,7 @@ describe("e2e: knowledge doc upload", () => {
       unsupportedDir,
       "--workspace-id",
       "ws_test",
+      "--dry-run",
     ]);
     expect(exitCode).toBe(2);
     expect(stderr).toMatch(/No supported files found/i);