fix(data): Task 1 review 修复（pycache清理+pytest.ini+错误处理）

- Fix 1: 移除误 commit 的 __pycache__ 文件
- Fix 2: 创建 pytest.ini 解决 PYTHONPATH 问题
- Fix 3: load_config 添加错误处理（FileNotFoundError + ValueError）

Co-Authored-By: Claude <noreply@anthropic.com>

tests/data/test_config.py

@@ -1,4 +1,5 @@
 # tests/data/test_config.py
+import pytest
 from sanguo_data.config import load_config, DataConfig
 
 def test_load_config_returns_dataconfig(tmp_path):
@@ -25,3 +26,7 @@ performance:
     assert cfg.data_paths["daily_dir"] == "/tmp/daily"
     assert cfg.data_sources["daily"][0]["name"] == "eastmoney"
     assert cfg.performance["max_retries"] == 3
+
+def test_load_config_raises_on_missing_file():
+    with pytest.raises(FileNotFoundError, match="配置文件不存在"):
+        load_config("/nonexistent/path/config.yaml")