fix: preserve exploration demonstration source and recording scope

tests/unit/test_exploration_synthesis.py

@@ -82,6 +82,45 @@ async def test_generation_is_idempotent_and_preserves_rerun_independence(synthes
     model.with_structured_output.return_value.ainvoke.assert_awaited_once()
 
 
+@pytest.mark.asyncio
+async def test_case_synthesis_receives_legacy_demonstration_platform(synthesis):
+    repository, session, run, model = synthesis
+    repository.database.put(
+        "exploration_demo",
+        "old-computer-demo",
+        {
+            "id": "old-computer-demo",
+            "exploration_id": session["id"],
+            "run_id": run["id"],
+            "source": "computer",
+            "status": "completed",
+            "media": [{"kind": "computer"}],
+        },
+    )
+    repository.add_message(
+        session["id"],
+        "浏览器中查看设置后返回首页",
+        "old-summary",
+        role="assistant",
+        metadata={"kind": "demonstration", "demonstration_id": "old-computer-demo"},
+    )
+    await generate_case(
+        repository, session["id"], "generate", run["id"], 0, ctx=SimpleNamespace(task_control=None)
+    )
+    messages = model.with_structured_output.return_value.ainvoke.await_args.args[0]
+    content = json.loads(messages[1].content)
+    assert content["demonstrations"] == [
+        {
+            "id": "old-computer-demo",
+            "run_id": run["id"],
+            "source": "computer",
+            "recorded_sources": ["computer"],
+        }
+    ]
+    assert "不能用手机上的成功证明电脑步骤完成" in messages[0].content
+    assert repository.run(run["id"])["outcome"]["test_result"]["status"] == "passed"
+
+
 @pytest.mark.asyncio
 async def test_synthesis_repairs_unbound_parameters_once_with_original_evidence(synthesis):
     repository, session, run, model = synthesis