test: add regression test for opengateway no-auth validation path

Ensures getProviderValidationError returns null when OPENAI_BASE_URL
points at opengateway.gitlawb.com and OPENAI_API_KEY is absent.

Author: professional-slacker

src/utils/providerValidation.test.ts

@@ -244,6 +244,14 @@ test('xiaomi mimo validation accepts MIMO_API_KEY without OPENAI_API_KEY', async
   await expect(getProviderValidationError(process.env)).resolves.toBeNull()
 })
 
+test('opengateway validation allows no-auth access without OPENAI_API_KEY', async () => {
+  process.env.CLAUDE_CODE_USE_OPENAI = '1'
+  process.env.OPENAI_BASE_URL = 'https://opengateway.gitlawb.com/v1'
+  delete process.env.OPENAI_API_KEY
+
+  await expect(getProviderValidationError(process.env)).resolves.toBeNull()
+})
+
 test('github validation stays descriptor-selected and reports missing auth', async () => {
   process.env.CLAUDE_CODE_USE_GITHUB = '1'
   delete process.env.CLAUDE_CODE_USE_OPENAI