refactor: finetune through LLMClient interface + get_running_loop

- Add submit_finetune and get_finetune_status abstract methods to LLMClient base
- Implement both methods in ZhipuAIClient using asyncio.get_running_loop()
- Rewrite finetune_service to call llm.submit_finetune / llm.get_finetune_status
  instead of accessing llm._client directly, restoring interface encapsulation
- Replace asyncio.get_event_loop() with get_running_loop() in ZhipuAIClient._call
  and all four methods in RustFSClient (deprecated in Python 3.10+)
- Update test_finetune_service to mock the LLMClient interface methods as AsyncMocks
- Add two new tests in test_llm_client for submit_finetune and get_finetune_status

tests/test_llm_client.py

@@ -38,3 +38,44 @@ async def test_llm_call_error_on_sdk_exception(client):
     client._client.chat.completions.create.side_effect = RuntimeError("quota exceeded")
     with pytest.raises(LLMCallError, match="大模型调用失败"):
         await client.chat("glm-4-flash", [{"role": "user", "content": "hi"}])
+
+
+@pytest.mark.asyncio
+async def test_submit_finetune_returns_job_id(client):
+    """submit_finetune should call the SDK and return the job id."""
+    resp = MagicMock()
+    resp.id = "glm-ft-newjob"
+    client._client.fine_tuning.jobs.create.return_value = resp
+
+    job_id = await client.submit_finetune(
+        jsonl_url="s3://bucket/train.jsonl",
+        base_model="glm-4",
+        hyperparams={"n_epochs": 2},
+    )
+
+    assert job_id == "glm-ft-newjob"
+    client._client.fine_tuning.jobs.create.assert_called_once_with(
+        training_file="s3://bucket/train.jsonl",
+        model="glm-4",
+        hyperparameters={"n_epochs": 2},
+    )
+
+
+@pytest.mark.asyncio
+async def test_get_finetune_status_returns_correct_dict(client):
+    """get_finetune_status should return a normalized dict with progress coerced to int."""
+    resp = MagicMock()
+    resp.id = "glm-ft-abc"
+    resp.status = "running"
+    resp.progress = "75"  # SDK may return string; should be coerced to int
+    resp.error_message = None
+    client._client.fine_tuning.jobs.retrieve.return_value = resp
+
+    result = await client.get_finetune_status("glm-ft-abc")
+
+    assert result == {
+        "job_id": "glm-ft-abc",
+        "status": "running",
+        "progress": 75,
+        "error_message": None,
+    }