Improve backtest lazy loading and test automation

.forgejo/workflows/ci.yaml

@@ -48,7 +48,7 @@ jobs:
           pip install nicegui fastapi uvicorn yfinance polars pandas pydantic pyyaml
           pip list
       - name: Run tests
-        run: pytest tests/test_pricing.py tests/test_strategies.py tests/test_portfolio.py -v --tb=short
+        run: pytest -v --tb=short
 
   type-check:
     runs-on: [linux, docker]