diff --git a/schemas/calculations.py b/schemas/calculations.py
index d560eeb..407812f 100644
--- a/schemas/calculations.py
+++ b/schemas/calculations.py
@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from typing import List, Optional
+from typing import List
 
 from pydantic import BaseModel, Field, PositiveFloat, ValidationError, field_validator
 
diff --git a/services/calculations.py b/services/calculations.py
index 0c570a1..ef82330 100644
--- a/services/calculations.py
+++ b/services/calculations.py
@@ -25,7 +25,6 @@ from schemas.calculations import (
     CapexCalculationResult,
     CapexCategoryBreakdown,
     CapexComponentInput,
-    CapexParameters,
     CapexTotals,
     CapexTimelineEntry,
     CashFlowEntry,
diff --git a/services/navigation.py b/services/navigation.py
index 6fa5fc4..4c097cf 100644
--- a/services/navigation.py
+++ b/services/navigation.py
@@ -1,11 +1,11 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from typing import Iterable, List, Optional, Sequence
+from typing import Iterable, List, Sequence
 
 from fastapi import Request
 
-from models.navigation import NavigationGroup, NavigationLink
+from models.navigation import NavigationLink
 from services.repositories import NavigationRepository
 from services.session import AuthSession
 
@@ -92,7 +92,7 @@ class NavigationService:
     ) -> List[NavigationLinkDTO]:
         resolved_roles = tuple(roles)
         mapped: List[NavigationLinkDTO] = []
-        for link in sorted(links, key=lambda l: (l.sort_order, l.id)):
+        for link in sorted(links, key=lambda x: (x.sort_order, x.id)):
             if not include_children and link.parent_link_id is not None:
                 continue
             if not include_disabled and (not link.is_enabled):
diff --git a/tests/test_project_scenario_models.py b/tests/test_project_scenario_models.py
index e90aa19..e674fd1 100644
--- a/tests/test_project_scenario_models.py
+++ b/tests/test_project_scenario_models.py
@@ -43,9 +43,9 @@ def session(engine) -> Iterator[Session]:
 def test_project_scenario_cascade_deletes(session: Session) -> None:
     project = Project(name="Cascade Mine",
                       operation_type=MiningOperationType.OTHER)
-    scenario_a = Scenario(
+    Scenario(
         name="Base Case", status=ScenarioStatus.DRAFT, project=project)
-    scenario_b = Scenario(
+    Scenario(
         name="Expansion", status=ScenarioStatus.DRAFT, project=project)
 
     session.add(project)