v9.5: 實作標籤完全不重疊算法

- 新增 _calculate_lane_conflicts_v2() 分開返回標籤重疊和線穿框分數
- 修改泳道選擇算法，優先選擇無標籤重疊的泳道
- 兩階段搜尋：優先側別無可用泳道則嘗試另一側
- 增強日誌輸出，顯示標籤範圍和詳細衝突分數

🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>

pytest.ini

@@ -0,0 +1,48 @@
+[pytest]
+# TimeLine Designer - Pytest Configuration
+# DocID: TDD-CONFIG-001
+
+# Test paths
+testpaths = tests
+
+# Python files and functions
+python_files = test_*.py
+python_classes = Test*
+python_functions = test_*
+
+# Output options
+addopts =
+    -v
+    --strict-markers
+    --tb=short
+    --cov=backend
+    --cov-report=html:docs/validation/coverage/htmlcov
+    --cov-report=term-missing
+    --cov-report=xml:docs/validation/coverage/coverage.xml
+
+# Markers
+markers =
+    unit: Unit tests
+    integration: Integration tests
+    e2e: End-to-end tests
+    performance: Performance tests
+    slow: Slow running tests
+
+# Coverage options
+[coverage:run]
+source = backend
+omit =
+    */tests/*
+    */venv/*
+    */__pycache__/*
+
+[coverage:report]
+exclude_lines =
+    pragma: no cover
+    def __repr__
+    raise AssertionError
+    raise NotImplementedError
+    if __name__ == .__main__.:
+    pass
+
+precision = 2