test(sandbox): update custom sandbox test with config initialization

Add Config initialization with accountId environment variable
to properly test default data endpoint behavior when not configured.

Updated the test case to include proper configuration setup
that was missing in the original test implementation.

test(sandbox): 更新自定义沙箱测试以包含配置初始化

添加 Config 初始化并设置 accountId 环境变量
以便在未配置时正确测试默认数据端点行为。

更新测试用例以包含适当的配置设置
这是原始测试实现中缺失的部分。

Change-Id: Ib7a3c632f6d5c669d476c4a2eccebf67b311258a
Signed-off-by: OhYee <oyohyee@oyohyee.com>

Author: OhYee

tests/unittests/sandbox/custom-sandbox.test.ts

@@ -126,11 +126,16 @@ describe('CustomSandbox', () => {
     });
 
     it('should use default data endpoint if not configured', () => {
+      // Set environment variable
+
       const baseSandbox = {
         sandboxId: 'sandbox-456',
       } as Sandbox;
 
-      const customSandbox = new CustomSandbox(baseSandbox);
+      // with env accountId=12345
+
+      const config = new Config({ accountId: '12345' });
+      const customSandbox = new CustomSandbox(baseSandbox, config);
 
       const baseUrl = customSandbox.getBaseUrl();
       expect(baseUrl).toContain('sandbox-456');