chore(lint): apply ruff --fix (4443 auto-fixes)

Auto-fixed categories:
- F401: unused imports removed
- I001: import blocks sorted
- W293: trailing whitespace stripped
- UP035: deprecated typing imports replaced
- SIM: simplify suggestions applied
- ARG: unused args prefixed with underscore
- T201: print statements removed
- F841: unused variables removed
- RUF059: unpacked variables prefixed

Remaining ~1500 unfixable errors (C901, B904, N806, E402) require manual work.

Backend smoke tests: 13/13 passed.

backend/tests/core/test_defensive_guards.py

@@ -1,15 +1,17 @@
+import shutil
 import sys
 from pathlib import Path
-import shutil
-import pytest
 from unittest.mock import MagicMock, patch
+
+import pytest
 from git.exc import InvalidGitRepositoryError
 
 sys.path.insert(0, str(Path(__file__).parent.parent.parent))
 
-from src.services.git_service import GitService
-from src.core.superset_client import SupersetClient
 from src.core.config_models import Environment
+from src.core.superset_client import SupersetClient
+from src.services.git_service import GitService
+
 
 # [DEF:test_git_service_get_repo_path_guard:Function]
 # @RELATION: BINDS_TO -> UnknownModule

backend/tests/core/test_git_service_gitea_pr.py

@@ -9,8 +9,8 @@ import asyncio
 import sys
 from pathlib import Path
 
-from fastapi import HTTPException
 import pytest
+from fastapi import HTTPException
 
 sys.path.insert(0, str(Path(__file__).parent.parent.parent))
 

backend/tests/core/test_mapping_service.py

@@ -4,21 +4,21 @@
 # @LAYER:     Domain
 # @RELATION:  VERIFIES ->[src.core.mapping_service.IdMappingService]
 #
+import sys
+from datetime import UTC, datetime
+from pathlib import Path
+
 import pytest
-from datetime import datetime, timezone
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
-import sys
-import os
-from pathlib import Path
 
 # Add backend directory to sys.path so 'src' can be resolved
 backend_dir = str(Path(__file__).parent.parent.parent.resolve())
 if backend_dir not in sys.path:
     sys.path.insert(0, backend_dir)
 
-from src.models.mapping import Base, ResourceMapping, ResourceType
 from src.core.mapping_service import IdMappingService
+from src.models.mapping import Base, ResourceMapping, ResourceType
 
 
 @pytest.fixture
@@ -80,7 +80,7 @@ def test_get_remote_id_returns_integer(db_session):
         uuid="uuid-1",
         remote_integer_id="99",
         resource_name="Test DS",
-        last_synced_at=datetime.now(timezone.utc),
+        last_synced_at=datetime.now(UTC),
     )
     db_session.add(mapping)
     db_session.commit()

backend/tests/core/test_migration_engine.py

@@ -4,24 +4,21 @@
 # @LAYER:     Domain
 # @RELATION: VERIFIES -> [src.core.migration_engine:Module]
 #
-import pytest
-import tempfile
 import json
-import yaml
-import zipfile
-import sys
 import os
+import sys
+import tempfile
+import zipfile
 from pathlib import Path
-from unittest.mock import MagicMock
+
+import pytest
+import yaml
 
 backend_dir = str(Path(__file__).parent.parent.parent.resolve())
 if backend_dir not in sys.path:
     sys.path.insert(0, backend_dir)
 
 from src.core.migration_engine import MigrationEngine
-from src.core.mapping_service import IdMappingService
-from src.models.mapping import ResourceType
-
 
 # --- Fixtures ---
 
@@ -80,7 +77,7 @@ def test_patch_dashboard_metadata_replaces_chart_ids():
 
         engine._patch_dashboard_metadata(fp, "target-env", source_map)
 
-        with open(fp, "r") as f:
+        with open(fp) as f:
             data = yaml.safe_load(f)
             result = json.loads(data["json_metadata"])
             assert (
@@ -107,7 +104,7 @@ def test_patch_dashboard_metadata_replaces_dataset_ids():
 
         engine._patch_dashboard_metadata(fp, "target-env", source_map)
 
-        with open(fp, "r") as f:
+        with open(fp) as f:
             data = yaml.safe_load(f)
             result = json.loads(data["json_metadata"])
             assert (
@@ -134,7 +131,7 @@ def test_patch_dashboard_metadata_skips_when_no_metadata():
 
         engine._patch_dashboard_metadata(fp, "target-env", {})
 
-        with open(fp, "r") as f:
+        with open(fp) as f:
             data = yaml.safe_load(f)
             assert "json_metadata" not in data
 
@@ -162,7 +159,7 @@ def test_patch_dashboard_metadata_handles_missing_targets():
 
         engine._patch_dashboard_metadata(fp, "target-env", source_map)
 
-        with open(fp, "r") as f:
+        with open(fp) as f:
             data = yaml.safe_load(f)
             result = json.loads(data["json_metadata"])
             targets = result["native_filter_configuration"][0]["targets"]
@@ -219,7 +216,7 @@ def test_transform_yaml_replaces_database_uuid():
 
         engine._transform_yaml(fp, {"source-uuid-abc": "target-uuid-xyz"})
 
-        with open(fp, "r") as f:
+        with open(fp) as f:
             data = yaml.safe_load(f)
             assert data["database_uuid"] == "target-uuid-xyz"
             assert data["table_name"] == "my_table"
@@ -243,7 +240,7 @@ def test_transform_yaml_ignores_unmapped_uuid():
 
         engine._transform_yaml(fp, {"other-uuid": "replacement"})
 
-        with open(fp, "r") as f:
+        with open(fp) as f:
             data = yaml.safe_load(f)
             assert data["database_uuid"] == "unknown-uuid"
 
@@ -317,12 +314,12 @@ def test_transform_zip_end_to_end():
             out_path = Path(out_dir)
 
             # Verify dataset transformation
-            with open(out_path / "datasets" / "ds.yaml", "r") as f:
+            with open(out_path / "datasets" / "ds.yaml") as f:
                 ds_data = yaml.safe_load(f)
                 assert ds_data["database_uuid"] == "target-db-uuid"
 
             # Verify dashboard patching
-            with open(out_path / "dashboards" / "db.yaml", "r") as f:
+            with open(out_path / "dashboards" / "db.yaml") as f:
                 db_data = yaml.safe_load(f)
                 meta = json.loads(db_data["json_metadata"])
                 assert (

backend/tests/scripts/test_clean_release_cli.py

@@ -5,21 +5,19 @@
 
 """Smoke tests for the redesigned clean release CLI commands."""
 
+from datetime import UTC, datetime
 from types import SimpleNamespace
-import json
-
-from src.dependencies import get_clean_release_repository, get_config_manager
-from datetime import datetime, timezone
 from uuid import uuid4
 
+from src.dependencies import get_clean_release_repository, get_config_manager
 from src.models.clean_release import (
     CleanPolicySnapshot,
     ComplianceReport,
     ReleaseCandidate,
     SourceRegistrySnapshot,
 )
-from src.services.clean_release.enums import CandidateStatus, ComplianceDecision
 from src.scripts.clean_release_cli import main as cli_main
+from src.services.clean_release.enums import CandidateStatus, ComplianceDecision
 
 
 # [DEF:test_cli_candidate_register_scaffold:Function]
@@ -227,7 +225,7 @@ def test_cli_release_gate_commands_scaffold() -> None:
             version="1.0.0",
             source_snapshot_ref="git:sha-approved",
             created_by="cli-test",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status=CandidateStatus.CHECK_PASSED.value,
         )
     )
@@ -237,7 +235,7 @@ def test_cli_release_gate_commands_scaffold() -> None:
             version="1.0.0",
             source_snapshot_ref="git:sha-rejected",
             created_by="cli-test",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status=CandidateStatus.CHECK_PASSED.value,
         )
     )
@@ -252,7 +250,7 @@ def test_cli_release_gate_commands_scaffold() -> None:
                 "violations_count": 0,
                 "blocking_violations_count": 0,
             },
-            generated_at=datetime.now(timezone.utc),
+            generated_at=datetime.now(UTC),
             immutable=True,
         )
     )
@@ -267,7 +265,7 @@ def test_cli_release_gate_commands_scaffold() -> None:
                 "violations_count": 0,
                 "blocking_violations_count": 0,
             },
-            generated_at=datetime.now(timezone.utc),
+            generated_at=datetime.now(UTC),
             immutable=True,
         )
     )

backend/tests/scripts/test_clean_release_tui.py

@@ -5,17 +5,16 @@
 # @LAYER: Scripts
 # @INVARIANT: TUI initializes, handles hotkeys (F5, F10) and safely falls back without TTY.
 
-import os
-import sys
 import curses
 import json
+import os
 from unittest import mock
 from unittest.mock import MagicMock, patch
 
 import pytest
 
-from src.scripts.clean_release_tui import CleanReleaseTUI, main, tui_main
 from src.models.clean_release import CheckFinalStatus
+from src.scripts.clean_release_tui import CleanReleaseTUI, main
 
 
 @pytest.fixture
@@ -63,17 +62,17 @@ def test_tui_initial_render(mock_curses_module, mock_stdscr: MagicMock):
 
     app = CleanReleaseTUI(mock_stdscr)
     assert app.status == "READY"
-    
+
     # We only want to run one loop iteration, so we mock getch to return F10
     mock_stdscr.getch.return_value = curses.KEY_F10
-    
+
     app.loop()
-    
+
     # Assert header was drawn
     addstr_calls = mock_stdscr.addstr.call_args_list
     assert any("Enterprise Clean Release Validator" in str(call) for call in addstr_calls)
     assert any("Candidate: [2026.03.03-rc1]" in str(call) for call in addstr_calls)
-    
+
     # Assert checks list is shown
     assert any("Data Purity" in str(call) for call in addstr_calls)
     assert any("Internal Sources Only" in str(call) for call in addstr_calls)
@@ -98,7 +97,7 @@ def test_tui_run_checks_f5(mock_curses_module, mock_stdscr: MagicMock):
     mock_curses_module.A_BOLD = 0
 
     app = CleanReleaseTUI(mock_stdscr)
-    
+
     # getch sequence:
     # 1. First loop: F5 (triggers run_checks)
     # 2. Next call after run_checks: F10 to exit
@@ -108,12 +107,12 @@ def test_tui_run_checks_f5(mock_curses_module, mock_stdscr: MagicMock):
             mock_stdscr.f5_pressed = True
             return curses.KEY_F5
         return curses.KEY_F10
-    
+
     mock_stdscr.getch.side_effect = side_effect
-    
+
     with mock.patch("time.sleep", return_value=None):
         app.loop()
-    
+
     # After F5 is pressed, status should be BLOCKED due to deliberate 'test-data' violation
     assert app.status == CheckFinalStatus.BLOCKED
     assert app.report_id is not None
@@ -132,13 +131,13 @@ def test_tui_exit_f10(mock_curses_module, mock_stdscr: MagicMock):
     """
     # Ensure constants match
     mock_curses_module.KEY_F10 = curses.KEY_F10
-    
+
     app = CleanReleaseTUI(mock_stdscr)
     mock_stdscr.getch.return_value = curses.KEY_F10
-    
+
     # loop() should return cleanly
     app.loop()
-    
+
     assert app.status == "READY"
 
 
@@ -159,12 +158,12 @@ def test_tui_clear_history_f7(mock_curses_module, mock_stdscr: MagicMock):
     app = CleanReleaseTUI(mock_stdscr)
     app.status = CheckFinalStatus.BLOCKED
     app.report_id = "SOME-REPORT"
-    
+
     # F7 then F10
     mock_stdscr.getch.side_effect = [curses.KEY_F7, curses.KEY_F10]
-    
+
     app.loop()
-    
+
     assert app.status == "READY"
     assert app.report_id is None
     assert len(app.checks_progress) == 0

backend/tests/services/clean_release/test_approval_service.py

@@ -7,7 +7,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 import pytest
 
@@ -35,7 +35,7 @@ def _seed_candidate_with_report(
             version="1.0.0",
             source_snapshot_ref="git:sha-approve-1",
             created_by="tester",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status=CandidateStatus.CHECK_PASSED.value,
         )
     )
@@ -50,7 +50,7 @@ def _seed_candidate_with_report(
                 "violations_count": 0,
                 "blocking_violations_count": 0 if report_status == ComplianceDecision.PASSED else 1,
             },
-            generated_at=datetime.now(timezone.utc),
+            generated_at=datetime.now(UTC),
             immutable=True,
         )
     )
@@ -96,7 +96,7 @@ def test_approve_rejects_foreign_report():
         candidate_id="cand-foreign-1",
         final_status=ComplianceDecision.PASSED.value,
         summary_json={"operator_summary": "foreign", "violations_count": 0, "blocking_violations_count": 0},
-        generated_at=datetime.now(timezone.utc),
+        generated_at=datetime.now(UTC),
         immutable=True,
     )
     repository.save_report(foreign_report)
@@ -175,8 +175,8 @@ def test_reject_persists_decision_without_promoting_candidate_state():
 # @POST: publish_candidate raises PublicationGateError.
 def test_reject_then_publish_is_blocked():
     from src.services.clean_release.approval_service import reject_candidate
-    from src.services.clean_release.publication_service import publish_candidate
     from src.services.clean_release.exceptions import PublicationGateError
+    from src.services.clean_release.publication_service import publish_candidate
 
     repository, candidate_id, report_id = _seed_candidate_with_report()
 
@@ -199,4 +199,4 @@ def test_reject_then_publish_is_blocked():
         )
 # [/DEF:test_reject_then_publish_is_blocked:Function]
 
-# [/DEF:TestApprovalService:Module]
+# [/DEF:TestApprovalService:Module]

backend/tests/services/clean_release/test_candidate_manifest_services.py

@@ -3,18 +3,19 @@
 # @PURPOSE: Test lifecycle and manifest versioning for release candidates.
 # @LAYER: Tests
 
+from datetime import UTC, datetime
+
 import pytest
-from datetime import datetime, timezone
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
+
 from src.core.database import Base
 from src.models.clean_release import (
-    ReleaseCandidate,
     DistributionManifest,
-    CandidateArtifact,
+    ReleaseCandidate,
 )
-from src.services.clean_release.enums import CandidateStatus
 from src.services.clean_release.candidate_service import register_candidate
+from src.services.clean_release.enums import CandidateStatus
 from src.services.clean_release.manifest_service import build_manifest_snapshot
 from src.services.clean_release.repository import CleanReleaseRepository
 
@@ -79,7 +80,7 @@ def test_manifest_versioning_and_immutability(db_session):
         artifacts_digest="hash1",
         source_snapshot_ref="ref1",
         content_json={},
-        created_at=datetime.now(timezone.utc),
+        created_at=datetime.now(UTC),
         created_by="operator",
     )
     db_session.add(m1)
@@ -93,7 +94,7 @@ def test_manifest_versioning_and_immutability(db_session):
         artifacts_digest="hash2",
         source_snapshot_ref="ref1",
         content_json={},
-        created_at=datetime.now(timezone.utc),
+        created_at=datetime.now(UTC),
         created_by="operator",
     )
     db_session.add(m2)

backend/tests/services/clean_release/test_compliance_execution_service.py

@@ -7,7 +7,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 import pytest
 
@@ -46,7 +46,7 @@ def _seed_with_candidate_policy_registry(
             version="1.0.0",
             source_snapshot_ref="git:sha-us2",
             created_by="tester",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status=CandidateStatus.MANIFEST_BUILT.value,
         )
     )
@@ -89,7 +89,7 @@ def _seed_with_candidate_policy_registry(
                     }
                 },
                 created_by="tester",
-                created_at=datetime.now(timezone.utc),
+                created_at=datetime.now(UTC),
                 immutable=True,
             )
         )

backend/tests/services/clean_release/test_compliance_task_integration.py

@@ -8,8 +8,8 @@
 from __future__ import annotations
 
 import asyncio
-from datetime import datetime, timezone
-from typing import Any, Dict
+from datetime import UTC, datetime
+from typing import Any
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -48,7 +48,7 @@ def _seed_repository(
             version="1.0.0",
             source_snapshot_ref="git:sha-task-int",
             created_by="tester",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status=CandidateStatus.MANIFEST_BUILT.value,
         )
     )
@@ -91,7 +91,7 @@ def _seed_repository(
                     }
                 },
                 created_by="tester",
-                created_at=datetime.now(timezone.utc),
+                created_at=datetime.now(UTC),
                 immutable=True,
             )
         )
@@ -114,7 +114,7 @@ class CleanReleaseCompliancePlugin:
     def name(self) -> str:
         return "clean_release_compliance"
 
-    def execute(self, params: Dict[str, Any], context=None):
+    def execute(self, params: dict[str, Any], context=None):
         orchestrator = CleanComplianceOrchestrator(params["repository"])
         run = orchestrator.start_check_run(
             candidate_id=params["candidate_id"],

backend/tests/services/clean_release/test_demo_mode_isolation.py

@@ -6,7 +6,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 from src.models.clean_release import ReleaseCandidate
 from src.services.clean_release.demo_data_service import (
@@ -65,7 +65,7 @@ def test_create_isolated_repository_keeps_mode_data_separate() -> None:
             version="1.0.0",
             source_snapshot_ref="git:sha-demo",
             created_by="demo-operator",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status="DRAFT",
         )
     )
@@ -75,7 +75,7 @@ def test_create_isolated_repository_keeps_mode_data_separate() -> None:
             version="1.0.0",
             source_snapshot_ref="git:sha-real",
             created_by="real-operator",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status="DRAFT",
         )
     )

backend/tests/services/clean_release/test_publication_service.py

@@ -7,7 +7,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 import pytest
 
@@ -35,7 +35,7 @@ def _seed_candidate_with_passed_report(
             version="1.0.0",
             source_snapshot_ref="git:sha-publish-1",
             created_by="tester",
-            created_at=datetime.now(timezone.utc),
+            created_at=datetime.now(UTC),
             status=candidate_status.value,
         )
     )
@@ -46,7 +46,7 @@ def _seed_candidate_with_passed_report(
             candidate_id=candidate_id,
             final_status=ComplianceDecision.PASSED.value,
             summary_json={"operator_summary": "seed", "violations_count": 0, "blocking_violations_count": 0},
-            generated_at=datetime.now(timezone.utc),
+            generated_at=datetime.now(UTC),
             immutable=True,
         )
     )
@@ -146,4 +146,4 @@ def test_republish_after_revoke_creates_new_active_record():
     assert second.status == PublicationStatus.ACTIVE.value
 # [/DEF:test_republish_after_revoke_creates_new_active_record:Function]
 
-# [/DEF:TestPublicationService:Module]
+# [/DEF:TestPublicationService:Module]

backend/tests/services/clean_release/test_report_audit_immutability.py

@@ -7,7 +7,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from unittest.mock import patch
 
 import pytest
@@ -15,13 +15,11 @@ import pytest
 from src.models.clean_release import (
     ComplianceReport,
     ComplianceRun,
-    ComplianceViolation,
 )
 from src.services.clean_release.audit_service import (
     audit_check_run,
     audit_preparation,
     audit_report,
-    audit_violation,
 )
 from src.services.clean_release.enums import ComplianceDecision, RunStatus
 from src.services.clean_release.report_builder import ComplianceReportBuilder
@@ -44,9 +42,9 @@ def _terminal_run(
         policy_snapshot_id="policy-immut-1",
         registry_snapshot_id="registry-immut-1",
         requested_by="tester",
-        requested_at=datetime.now(timezone.utc),
-        started_at=datetime.now(timezone.utc),
-        finished_at=datetime.now(timezone.utc),
+        requested_at=datetime.now(UTC),
+        started_at=datetime.now(UTC),
+        finished_at=datetime.now(UTC),
         status=RunStatus.SUCCEEDED,
         final_status=final_status,
     )
@@ -93,7 +91,7 @@ def test_repository_rejects_report_overwrite_for_same_report_id():
             "violations_count": 0,
             "blocking_violations_count": 0,
         },
-        generated_at=datetime.now(timezone.utc),
+        generated_at=datetime.now(UTC),
         immutable=True,
     )
     mutated = ComplianceReport(
@@ -106,7 +104,7 @@ def test_repository_rejects_report_overwrite_for_same_report_id():
             "violations_count": 1,
             "blocking_violations_count": 1,
         },
-        generated_at=datetime.now(timezone.utc),
+        generated_at=datetime.now(UTC),
         immutable=True,
     )
 

backend/tests/services/dataset_review/test_superset_matrix.py

@@ -8,16 +8,14 @@
 from types import SimpleNamespace
 from unittest.mock import MagicMock
 
-# Import models to ensure proper SQLAlchemy registration
-from src.models.auth import User
-from src.models.dataset_review import CompiledPreview
-
 from src.core.utils.superset_compilation_adapter import (
     PreviewCompilationPayload,
     SqlLabLaunchPayload,
     SupersetCompilationAdapter,
 )
 
+# Import models to ensure proper SQLAlchemy registration
+
 
 # [DEF:make_adapter:Function]
 # @PURPOSE: Build an adapter with a mock Superset client and deterministic environment for compatibility tests.

backend/tests/test_auth.py

@@ -13,16 +13,17 @@ from pathlib import Path
 sys.path.append(str(Path(__file__).parent.parent / "src"))
 
 import pytest
+from cryptography.fernet import Fernet
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
-from cryptography.fernet import Fernet
-from src.core.database import Base
-from src.models.auth import User, Role, Permission, ADGroupMapping
-from src.services.auth_service import AuthService
+
 from src.core.auth.repository import AuthRepository
-from src.core.auth.security import verify_password, get_password_hash
+from src.core.auth.security import get_password_hash, verify_password
+from src.core.database import Base
+from src.models.auth import ADGroupMapping, Permission, Role, User
 from src.scripts.create_admin import create_admin
 from src.scripts.init_auth_db import ensure_encryption_key
+from src.services.auth_service import AuthService
 
 # Create in-memory SQLite database for testing
 SQLALCHEMY_DATABASE_URL = "sqlite:///:memory:"

backend/tests/test_core_scheduler.py

@@ -10,11 +10,9 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
-import pytest
 from unittest.mock import MagicMock, patch
-from datetime import datetime, timezone
-from apscheduler.schedulers.background import BackgroundScheduler
 
+from apscheduler.schedulers.background import BackgroundScheduler
 
 # ---------------------------------------------------------------------------
 # Helpers — fresh scheduler & mock config

backend/tests/test_dashboards_api.py

@@ -3,24 +3,26 @@
 # @PURPOSE: Comprehensive contract-driven tests for Dashboard Hub API
 # @LAYER: Domain (Tests)
 # @SEMANTICS: tests, dashboards, api, contract, remediation
+from datetime import UTC, datetime
+from unittest.mock import AsyncMock, MagicMock, patch
+
 import pytest
 from fastapi.testclient import TestClient
-from unittest.mock import MagicMock, patch, AsyncMock
-from datetime import datetime, timezone
-from src.app import app
+
 from src.api.routes.dashboards import (
-    DashboardsResponse,
     DashboardDetailResponse,
+    DashboardsResponse,
     DashboardTaskHistoryResponse,
     DatabaseMappingsResponse,
 )
+from src.app import app
 from src.dependencies import (
-    get_current_user,
-    has_permission,
     get_config_manager,
-    get_task_manager,
-    get_resource_service,
+    get_current_user,
     get_mapping_service,
+    get_resource_service,
+    get_task_manager,
+    has_permission,
 )
 
 # Global mock user
@@ -299,7 +301,7 @@ def test_get_dashboard_detail_env_not_found(mock_deps):
 # [DEF:test_get_dashboard_tasks_history_success:Function]
 # @RELATION: BINDS_TO ->[TestDashboardsApi]
 def test_get_dashboard_tasks_history_success(mock_deps):
-    now = datetime.now(timezone.utc)
+    now = datetime.now(UTC)
     task1 = MagicMock(
         id="t1",
         plugin_id="superset-backup",
@@ -328,7 +330,7 @@ def test_get_dashboard_tasks_history_sorting(mock_deps):
     """@POST: Response contains sorted task history (newest first)."""
     from datetime import timedelta
 
-    now = datetime.now(timezone.utc)
+    now = datetime.now(UTC)
     older = now - timedelta(hours=2)
     newest = now
 

backend/tests/test_log_persistence.py

@@ -11,9 +11,10 @@ from unittest.mock import patch
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 
-from src.models.mapping import Base
-from src.core.task_manager.persistence import TaskLogPersistenceService
 from src.core.task_manager.models import LogEntry, LogFilter
+from src.core.task_manager.persistence import TaskLogPersistenceService
+from src.models.mapping import Base
+
 # [/SECTION]
 
 # [DEF:TestLogPersistence:Class]

backend/tests/test_logger.py

@@ -5,18 +5,19 @@
 # @RELATION: VERIFIES -> src/core/logger.py
 # @INVARIANT: All required log statements must correctly check the threshold.
 
-import pytest
 import logging
 
+import pytest
+
+from src.core.config_models import LoggingConfig
 from src.core.logger import (
+    CotJsonFormatter,
     belief_scope,
-    logger,
     configure_logger,
     get_task_log_level,
+    logger,
     should_log_task_level,
-    CotJsonFormatter,
 )
-from src.core.config_models import LoggingConfig
 
 
 @pytest.fixture(autouse=True)
@@ -101,9 +102,8 @@ def test_belief_scope_error_handling(caplog):
 
     caplog.set_level("DEBUG")
 
-    with pytest.raises(ValueError):
-        with belief_scope("FailingFunction"):
-            raise ValueError("Something went wrong")
+    with pytest.raises(ValueError), belief_scope("FailingFunction"):
+        raise ValueError("Something went wrong")
 
     # Check that an EXPLORE marker was emitted
     explore_records = [
@@ -294,7 +294,6 @@ def test_enable_belief_state_flag(caplog):
 def test_cot_json_formatter_output():
     """Test that CotJsonFormatter produces valid JSON with expected fields."""
     import json
-    from datetime import datetime, timezone
 
     formatter = CotJsonFormatter()
 

backend/tests/test_models.py

@@ -1,6 +1,7 @@
 from src.core.config_models import Environment
 from src.core.logger import belief_scope
 
+
 # [DEF:test_environment_model:Function]
 # @RELATION: TESTS -> Environment
 # @PURPOSE: Tests that Environment model correctly stores values.

backend/tests/test_resource_hubs.py

@@ -4,14 +4,16 @@
 # @SEMANTICS: tests, resource-hubs, dashboards, datasets, pagination, api
 # @PURPOSE: Contract tests for resource hub dashboards/datasets listing and pagination boundary validation.
 # @LAYER: Domain (Tests)
+from unittest.mock import AsyncMock, MagicMock
+
 import pytest
 from fastapi.testclient import TestClient
-from unittest.mock import MagicMock, AsyncMock
+
 from src.app import app
 from src.dependencies import (
     get_config_manager,
-    get_task_manager,
     get_resource_service,
+    get_task_manager,
     has_permission,
 )
 

backend/tests/test_smoke_app.py

@@ -64,11 +64,11 @@ def test_app_has_expected_middleware():
 def test_cot_logger_imports():
     """Core logging infrastructure is importable."""
     from src.core.cot_logger import (
-        log,
-        seed_trace_id,
         get_trace_id,
-        push_span,
+        log,
         pop_span,
+        push_span,
+        seed_trace_id,
     )
 
     tid = seed_trace_id()

backend/tests/test_smoke_plugins.py

@@ -1,9 +1,10 @@
+import os
 import sys
 from pathlib import Path
-import os
-import pytest
 from unittest.mock import MagicMock, patch
 
+import pytest
+
 sys.path.insert(0, str(Path(__file__).parent.parent))
 
 # Mock database before any modules that import it are loaded
@@ -22,18 +23,18 @@ class TestPluginSmoke:
         syntax errors, missing class declarations).
         """
         from src.core.plugin_loader import PluginLoader
-        
+
         plugin_dir = os.path.join(str(Path(__file__).parent.parent), "src", "plugins")
-        
+
         # This will discover and instantiate plugins
         loader = PluginLoader(plugin_dir)
 
         plugins = loader.get_all_plugin_configs()
         plugin_ids = {p.id for p in plugins}
-        
+
         # We expect at least the migration and git plugins to be present
         expected_plugins = {"superset-migration", "git-integration"}
-        
+
         missing_plugins = expected_plugins - plugin_ids
         assert not missing_plugins, f"Missing expected plugins: {missing_plugins}"
 
@@ -44,21 +45,21 @@ class TestPluginSmoke:
         """
         from src.core.plugin_loader import PluginLoader
         from src.core.task_manager.manager import TaskManager
-        
+
         plugin_dir = os.path.join(str(Path(__file__).parent.parent), "src", "plugins")
         loader = PluginLoader(plugin_dir)
-        
+
         # Initialize TaskManager with real loader
         with patch("src.core.task_manager.manager.TaskPersistenceService") as MockPersistence, \
              patch("src.core.task_manager.manager.TaskLogPersistenceService"):
-             
+
             MockPersistence.return_value.load_tasks.return_value = []
-            
+
             with patch("src.dependencies.config_manager"):
                 manager = TaskManager(loader)
-            
+
             # Stop the flusher thread to prevent hanging
             manager._flusher_stop_event.set()
             manager._flusher_thread.join(timeout=2)
-            
+
             assert manager is not None

backend/tests/test_task_manager.py

@@ -7,12 +7,14 @@
 
 import sys
 from pathlib import Path
+
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
-import pytest
 import asyncio
-from unittest.mock import MagicMock, patch, AsyncMock
 from datetime import datetime
+from unittest.mock import MagicMock, patch
+
+import pytest
 
 
 # Helper to create a TaskManager with mocked dependencies

backend/tests/test_task_persistence.py

@@ -6,16 +6,17 @@
 # @TEST_DATA: valid_task -> {"id": "test-uuid-1", "plugin_id": "backup", "status": "PENDING"}
 
 # [SECTION: IMPORTS]
-from datetime import datetime, timedelta
+from datetime import datetime
 from unittest.mock import patch
 
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 
+from src.core.task_manager.models import LogEntry, Task, TaskStatus
+from src.core.task_manager.persistence import TaskPersistenceService
 from src.models.mapping import Base, Environment
 from src.models.task import TaskRecord
-from src.core.task_manager.persistence import TaskPersistenceService
-from src.core.task_manager.models import Task, TaskStatus, LogEntry
+
 # [/SECTION]
 
 

backend/tests/test_translate_corrections.py

@@ -27,19 +27,17 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
-import pytest
 from unittest.mock import MagicMock
+
+import pytest
 from fastapi.testclient import TestClient
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
-from datetime import datetime, timezone
-import uuid
 
-from src.core.database import Base
 from src.app import app
-from src.dependencies import get_current_user, get_config_manager, has_permission, get_db
+from src.core.database import Base
+from src.dependencies import get_config_manager, get_current_user, get_db
 from src.plugins.translate.dictionary import DictionaryManager
-from src.models.translate import TerminologyDictionary, DictionaryEntry
 
 # In-memory SQLite
 SQLALCHEMY_DATABASE_URL = "sqlite:///:memory:"

backend/tests/test_translate_executor_filter.py

@@ -14,12 +14,10 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
-import pytest
 from unittest.mock import MagicMock
 
 from src.plugins.translate.executor import TranslationExecutor
 
-
 # ---------------------------------------------------------------------------
 # Helpers
 # ---------------------------------------------------------------------------

backend/tests/test_translate_history.py

@@ -26,20 +26,19 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
+import uuid
+from datetime import UTC, datetime
+from unittest.mock import MagicMock
+
 import pytest
-from unittest.mock import MagicMock, patch
 from fastapi.testclient import TestClient
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
-from datetime import datetime, timezone
-import uuid
-import json
 
-from src.core.database import Base
 from src.app import app
-from src.dependencies import get_current_user, get_config_manager, has_permission, get_db
-from src.plugins.translate.metrics import TranslationMetrics
-from src.models.translate import TranslationJob, TranslationRun, TranslationEvent, MetricSnapshot
+from src.core.database import Base
+from src.dependencies import get_config_manager, get_current_user, get_db
+from src.models.translate import TranslationEvent, TranslationJob, TranslationRun
 
 # In-memory SQLite
 SQLALCHEMY_DATABASE_URL = "sqlite:///:memory:"
@@ -130,7 +129,7 @@ def _create_test_run(db_session, job_id: str, status: str = "COMPLETED", trigger
         dict_snapshot_hash="def456",
         key_hash="ghi789",
         created_by="testuser",
-        created_at=datetime.now(timezone.utc),
+        created_at=datetime.now(UTC),
     )
     db_session.add(run)
     db_session.flush()
@@ -197,7 +196,7 @@ def test_list_runs_filter_status(client, mock_api_deps):
     _create_test_run(session, job.id, status="FAILED")
     session.commit()
 
-    response = client.get(f"/api/translate/runs?run_status=FAILED")
+    response = client.get("/api/translate/runs?run_status=FAILED")
     assert response.status_code == 200
     data = response.json()
     for item in data["items"]:
@@ -221,7 +220,7 @@ def test_get_run_detail(client, mock_api_deps):
         event_type="RUN_STARTED",
         event_data={},
         created_by="testuser",
-        created_at=datetime.now(timezone.utc),
+        created_at=datetime.now(UTC),
     )
     session.add(event)
     session.commit()

backend/tests/test_translate_jobs.py

@@ -29,26 +29,20 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
+from unittest.mock import MagicMock
+
 import pytest
-from unittest.mock import MagicMock, patch
-from datetime import datetime, timezone
-from fastapi import status
 from fastapi.testclient import TestClient
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
-from typing import Any, Dict, List, Optional, Tuple
-import json
-import uuid
 
-from src.core.database import Base
 from src.app import app
-from src.dependencies import (
-    get_current_user,
-    get_config_manager,
-    has_permission,
-)
 from src.core.config_models import Environment
-
+from src.core.database import Base
+from src.dependencies import (
+    get_config_manager,
+    get_current_user,
+)
 
 # [DEF:valid_job_payload:Variable]
 # @PURPOSE: Standard valid payload for creating a translation job.

backend/tests/test_translate_scheduler.py

@@ -26,20 +26,16 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
-import pytest
 from unittest.mock import MagicMock
+
+import pytest
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
-from datetime import datetime, timezone
-import uuid
 
 from src.core.database import Base
-from src.app import app
-from src.dependencies import get_current_user, get_config_manager, get_db
-from src.plugins.translate.scheduler import TranslationScheduler, execute_scheduled_translation
+from src.plugins.translate.scheduler import TranslationScheduler
 from src.plugins.translate.service import TranslateJobService
 from src.schemas.translate import TranslateJobCreate
-from src.models.translate import TranslationJob, TranslationSchedule, TranslationRun
 
 # In-memory SQLite
 SQLALCHEMY_DATABASE_URL = "sqlite:///:memory:"
@@ -63,7 +59,6 @@ def db_session():
 # @PURPOSE: Verify schedule creation with valid params.
 def test_create_schedule(db_session):
     """Test creating a schedule for a job."""
-    from src.core.config_models import Environment
     config_mgr = MagicMock()
     config_mgr.get_environments.return_value = []
 
@@ -90,7 +85,6 @@ def test_create_schedule(db_session):
 # @PURPOSE: Verify schedule update.
 def test_update_schedule(db_session):
     """Test updating a schedule."""
-    from src.core.config_models import Environment
     config_mgr = MagicMock()
     config_mgr.get_environments.return_value = []
 
@@ -111,7 +105,6 @@ def test_update_schedule(db_session):
 # @PURPOSE: Verify schedule deletion.
 def test_delete_schedule(db_session):
     """Test deleting a schedule."""
-    from src.core.config_models import Environment
     config_mgr = MagicMock()
     config_mgr.get_environments.return_value = []
 
@@ -131,7 +124,6 @@ def test_delete_schedule(db_session):
 # @PURPOSE: Verify enable/disable toggle.
 def test_enable_disable_schedule(db_session):
     """Test enabling and disabling a schedule."""
-    from src.core.config_models import Environment
     config_mgr = MagicMock()
     config_mgr.get_environments.return_value = []
 
@@ -153,7 +145,6 @@ def test_enable_disable_schedule(db_session):
 # @PURPOSE: Verify ValueError on getting non-existent schedule.
 def test_get_schedule_not_found(db_session):
     """Test that getting a non-existent schedule raises ValueError."""
-    from src.core.config_models import Environment
     config_mgr = MagicMock()
     config_mgr.get_environments.return_value = []
 
@@ -167,7 +158,6 @@ def test_get_schedule_not_found(db_session):
 # @PURPOSE: Verify listing only active schedules.
 def test_list_active_schedules(db_session):
     """Test listing active schedules."""
-    from src.core.config_models import Environment
     config_mgr = MagicMock()
     config_mgr.get_environments.return_value = []
 

backend/tests/test_translate_scheduler_execution.py

@@ -9,10 +9,10 @@
 # @TEST_INVARIANT: trigger_type_dispatch -> VERIFIED_BY: [test_new_key_only_mode, test_baseline_expired_fallback, test_full_mode_default]
 import sys
 from pathlib import Path
-sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
-from unittest.mock import MagicMock, patch
-from datetime import datetime, timezone, timedelta
 
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+from datetime import UTC, datetime, timedelta
+from unittest.mock import MagicMock, patch
 
 # -- Helpers -----------------------------------------------------------------
 
@@ -23,7 +23,7 @@ def _make_most_recent_run(created_at_delta_days=60):
     run.job_id = "job-1"
     run.status = "COMPLETED"
     run.insert_status = "succeeded"
-    run.created_at = datetime.now(timezone.utc) - timedelta(days=created_at_delta_days)
+    run.created_at = datetime.now(UTC) - timedelta(days=created_at_delta_days)
     return run
 
 

backend/tests/test_translate_scheduler_guard.py

@@ -13,10 +13,8 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
-import pytest
+from datetime import UTC, datetime, timedelta
 from unittest.mock import MagicMock, patch
-from datetime import datetime, timezone, timedelta
-
 
 # ---------------------------------------------------------------------------
 # Helpers
@@ -29,7 +27,7 @@ def _make_most_recent_run(created_at_delta_days=60):
     run.job_id = "job-1"
     run.status = "COMPLETED"
     run.insert_status = "succeeded"
-    run.created_at = datetime.now(timezone.utc) - timedelta(days=created_at_delta_days)
+    run.created_at = datetime.now(UTC) - timedelta(days=created_at_delta_days)
     return run
 
 
@@ -85,20 +83,19 @@ def test_concurrent_run_skips():
 
     with patch(
         "src.plugins.translate.orchestrator.TranslationOrchestrator"
-    ) as mock_orch_cls:
-        with patch(
-            "src.plugins.translate.scheduler.TranslationEventLog"
-        ) as mock_event_log_cls:
-            mock_event_log = MagicMock()
-            mock_event_log_cls.return_value = mock_event_log
+    ) as mock_orch_cls, patch(
+        "src.plugins.translate.scheduler.TranslationEventLog"
+    ) as mock_event_log_cls:
+        mock_event_log = MagicMock()
+        mock_event_log_cls.return_value = mock_event_log
 
-            execute_scheduled_translation(
-                schedule_id="sched-1",
-                job_id="job-1",
-                db_session_maker=mock_session_maker,
-                config_manager=mock_config,
-                execution_mode="full",
-            )
+        execute_scheduled_translation(
+            schedule_id="sched-1",
+            job_id="job-1",
+            db_session_maker=mock_session_maker,
+            config_manager=mock_config,
+            execution_mode="full",
+        )
 
     mock_orch_cls.assert_not_called()
     mock_event_log.log_event.assert_called_once()
@@ -128,7 +125,7 @@ def test_recent_pending_run_not_stale():
     pending_run.id = "pending-run-1"
     pending_run.job_id = "job-1"
     pending_run.status = "PENDING"
-    pending_run.created_at = datetime.now(timezone.utc) - timedelta(minutes=30)
+    pending_run.created_at = datetime.now(UTC) - timedelta(minutes=30)
 
     q1 = MagicMock()
     q1.filter.return_value.first.return_value = schedule
@@ -140,20 +137,19 @@ def test_recent_pending_run_not_stale():
 
     with patch(
         "src.plugins.translate.orchestrator.TranslationOrchestrator"
-    ) as mock_orch_cls:
-        with patch(
-            "src.plugins.translate.scheduler.TranslationEventLog"
-        ) as mock_event_log_cls:
-            mock_event_log = MagicMock()
-            mock_event_log_cls.return_value = mock_event_log
+    ) as mock_orch_cls, patch(
+        "src.plugins.translate.scheduler.TranslationEventLog"
+    ) as mock_event_log_cls:
+        mock_event_log = MagicMock()
+        mock_event_log_cls.return_value = mock_event_log
 
-            execute_scheduled_translation(
-                schedule_id="sched-1",
-                job_id="job-1",
-                db_session_maker=mock_session_maker,
-                config_manager=mock_config,
-                execution_mode="full",
-            )
+        execute_scheduled_translation(
+            schedule_id="sched-1",
+            job_id="job-1",
+            db_session_maker=mock_session_maker,
+            config_manager=mock_config,
+            execution_mode="full",
+        )
 
     mock_orch_cls.assert_not_called()
     mock_event_log.log_event.assert_called_once()
@@ -183,7 +179,7 @@ def test_stale_pending_cleared_and_proceeds():
     stale_run.id = "stale-run-1"
     stale_run.job_id = "job-1"
     stale_run.status = "PENDING"
-    stale_run.created_at = datetime.now(timezone.utc) - timedelta(hours=2)
+    stale_run.created_at = datetime.now(UTC) - timedelta(hours=2)
 
     most_recent = _make_most_recent_run(created_at_delta_days=30)
 
@@ -248,13 +244,13 @@ def test_multiple_stale_pending_all_cleared():
     stale_run_a.id = "stale-run-a"
     stale_run_a.job_id = "job-1"
     stale_run_a.status = "PENDING"
-    stale_run_a.created_at = datetime.now(timezone.utc) - timedelta(hours=5)
+    stale_run_a.created_at = datetime.now(UTC) - timedelta(hours=5)
 
     stale_run_b = MagicMock()
     stale_run_b.id = "stale-run-b"
     stale_run_b.job_id = "job-1"
     stale_run_b.status = "PENDING"
-    stale_run_b.created_at = datetime.now(timezone.utc) - timedelta(hours=3)
+    stale_run_b.created_at = datetime.now(UTC) - timedelta(hours=3)
 
     most_recent = _make_most_recent_run(created_at_delta_days=30)