fix: ruff lint fixes for v3 test files

tests/test_pbt_v3_decision.py

@@ -13,13 +13,9 @@ from hypothesis import given, settings
 from hypothesis import strategies as st
 
 from services.trading.position_sizer import (
-    KellySizingResult,
     compute_kelly_sizing,
-    compute_reward_ratio,
 )
 from services.trading.stop_loss_manager import (
-    TrailingStopResult,
-    V3StopLevels,
     compute_trailing_stop,
     compute_v3_stops,
 )