fix: lint errors (import sorting, unused vars)

services/aggregation/projection.py

@@ -16,7 +16,7 @@ from datetime import datetime, timezone
 
 import asyncpg
 
-from services.shared.schemas import TrendDirection, TrendSummary
+from services.shared.schemas import TrendSummary
 
 logger = logging.getLogger("projection")
 
@@ -169,10 +169,8 @@ def project_macro_decay(
 
         # Decay factor: ratio of future impact to current impact
         if half_life > 0:
-            current_factor = math.pow(2.0, -current_age_days / half_life)
             future_factor = math.pow(2.0, -future_age_days / half_life)
         else:
-            current_factor = 0.0
             future_factor = 0.0
 
         severity_w = _SEVERITY_WEIGHT.get(ev.severity, 0.25)