fix: sync __version__ with pyproject and pin test to single source

tests/unit/test_package.py

@@ -1,10 +1,15 @@
 """包基线冒烟测试：可导入、版本号存在。"""
 
+from pathlib import Path
+
 import polygateway
 
 
 def test_package_importable_with_version() -> None:
-    assert polygateway.__version__ == "0.1.0"
+    import tomllib
+
+    declared = tomllib.loads(Path("pyproject.toml").read_text())["project"]["version"]
+    assert polygateway.__version__ == declared  # 单一版本源: 与 pyproject 同步
 
 
 def test_ocr_public_surface_exported():