feat(factor): 因子表达式注册 + Alpha158 子集内置库

- 实现因子表达式注册表（registry.py）
- 实现 Alpha158 子集内置因子库（library.py）
- 使用 vnpy.alpha ts_ 算子语法（ts_mean, ts_delta, ts_max, ts_min）
- 修正列名：close/open/high/low/volume（非 _price 后缀）
- TDD 实现：8 测试全部通过
- 支持因子分类过滤（custom/builtin）
- 防止重复注册

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

tests/factor/test_library.py

@@ -0,0 +1,29 @@
+"""内置因子库测试."""
+from sanguo_factor.registry import list_factors, get_factor, _REGISTRY
+import importlib
+import sanguo_factor.library
+
+
+def test_library_registers_on_import():
+    """测试导入时自动注册内置因子."""
+    _REGISTRY.clear()
+    importlib.reload(sanguo_factor.library)
+    assert len(list_factors(category="builtin")) > 0
+
+
+def test_builtin_factors_count():
+    """测试内置因子数量正确."""
+    _REGISTRY.clear()
+    importlib.reload(sanguo_factor.library)
+    builtin_factors = list_factors(category="builtin")
+    assert len(builtin_factors) == 7
+
+
+def test_builtin_factor_expressions():
+    """测试内置因子表达式格式正确."""
+    _REGISTRY.clear()
+    importlib.reload(sanguo_factor.library)
+    ma5 = get_factor("ma5")
+    assert ma5 is not None
+    assert ma5["category"] == "builtin"
+    assert "ts_mean(close, 5)" in ma5["expression"]

tests/factor/test_registry.py

@@ -0,0 +1,43 @@
+"""因子表达式注册表测试."""
+import pytest
+from sanguo_factor.registry import register_factor, get_factor, list_factors, _REGISTRY
+
+
+def test_register_and_get_factor():
+    """测试注册和获取因子."""
+    _REGISTRY.clear()
+    register_factor("ma5", "ts_mean(close, 5)", category="trend")
+    f = get_factor("ma5")
+    assert f["name"] == "ma5"
+    assert f["category"] == "trend"
+    assert f["expression"] == "ts_mean(close, 5)"
+
+
+def test_list_factors_by_category():
+    """测试按分类列出因子."""
+    _REGISTRY.clear()
+    register_factor("ma5", "ts_mean(close, 5)", category="trend")
+    register_factor("rsi", "ts_rank(close, 14)", category="momentum")
+    assert len(list_factors(category="trend")) == 1
+    assert len(list_factors()) == 2
+
+
+def test_register_duplicate_raises():
+    """测试重复注册抛出异常."""
+    _REGISTRY.clear()
+    register_factor("ma5", "ts_mean(close, 5)", category="trend")
+    with pytest.raises(ValueError, match="因子已存在"):
+        register_factor("ma5", "ts_mean(close, 10)", category="trend")
+
+
+def test_get_nonexistent_factor_returns_none():
+    """测试获取不存在的因子返回 None."""
+    _REGISTRY.clear()
+    assert get_factor("nonexistent") is None
+
+
+def test_list_factors_empty_registry():
+    """测试空注册表返回空列表."""
+    _REGISTRY.clear()
+    assert list_factors() == []
+    assert list_factors(category="trend") == []