test(deepseek): print vision failure facts

packages/llm/llm-deepseek/tests/adapter.e2e.ts

@@ -178,7 +178,10 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY)('llm-deepseek e2e (real API)', ()
         })],
         maxTokens: 100,
       })
-      expect(result.finish).toMatchObject({ kind: 'stop' })
+      expect(
+        result.finish.kind,
+        `DeepSeek vision result: ${JSON.stringify(result.finish)}`,
+      ).toBe('stop')
       expect(textOf(result).trim().length).toBeGreaterThan(0)
       expect(uploadedFile).toMatch(/^file-api-/u)
     } finally {