chore(backend): deprecation sweep — Pydantic V1 -> V2, utcnow -> tz-aware

Two low-risk Pydantic V1 idioms that will be hard errors in V3:
  - Query(regex=...) -> Query(pattern=...) (audit_routes, control_generator_routes)
  - class Config: from_attributes=True -> model_config = ConfigDict(...)
    in source_policy_router.py (schemas.py is intentionally skipped — it is
    the Phase 1 schema-split target and the ConfigDict conversion is most
    efficient to do during that split).

Naive -> aware datetime sweep across 47 files:
  - datetime.utcnow() -> datetime.now(timezone.utc)
  - default=datetime.utcnow -> default=lambda: datetime.now(timezone.utc)
  - onupdate=datetime.utcnow -> onupdate=lambda: datetime.now(timezone.utc)

All SQLAlchemy DateTime columns in the project already declare
timezone=True, so the DB schema expects aware datetimes. Before this
commit, the in-Python side was generating naive values and the driver
was silently coercing them. This is a latent-bug fix, not a behavior
change at the DB boundary.

Verified:
  - 173/173 pytest compliance/tests/ pass (same as baseline)
  - tests/contracts/test_openapi_baseline.py passes (360 paths,
    484 operations unchanged)
  - DeprecationWarning count dropped from 158 -> 35

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend-compliance/compliance/tests/test_audit_routes.py

@@ -8,7 +8,7 @@ Run with: pytest backend/compliance/tests/test_audit_routes.py -v
 
 import pytest
 import hashlib
-from datetime import datetime
+from datetime import datetime, timezone
 from unittest.mock import MagicMock
 from uuid import uuid4
 
@@ -78,7 +78,7 @@ def sample_session():
         completed_items=0,
         compliant_count=0,
         non_compliant_count=0,
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -94,7 +94,7 @@ def sample_signoff(sample_session, sample_requirement):
         signature_hash=None,
         signed_at=None,
         signed_by=None,
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -214,7 +214,7 @@ class TestAuditSessionLifecycle:
         assert sample_session.status == AuditSessionStatusEnum.DRAFT
 
         sample_session.status = AuditSessionStatusEnum.IN_PROGRESS
-        sample_session.started_at = datetime.utcnow()
+        sample_session.started_at = datetime.now(timezone.utc)
 
         assert sample_session.status == AuditSessionStatusEnum.IN_PROGRESS
         assert sample_session.started_at is not None
@@ -231,7 +231,7 @@ class TestAuditSessionLifecycle:
         sample_session.status = AuditSessionStatusEnum.IN_PROGRESS
 
         sample_session.status = AuditSessionStatusEnum.COMPLETED
-        sample_session.completed_at = datetime.utcnow()
+        sample_session.completed_at = datetime.now(timezone.utc)
 
         assert sample_session.status == AuditSessionStatusEnum.COMPLETED
         assert sample_session.completed_at is not None
@@ -353,7 +353,7 @@ class TestSignOff:
     def test_signoff_with_signature_creates_hash(self, sample_session, sample_requirement):
         """Signing off with signature should create SHA-256 hash."""
         result = AuditResultEnum.COMPLIANT
-        timestamp = datetime.utcnow().isoformat()
+        timestamp = datetime.now(timezone.utc).isoformat()
         data = f"{result.value}|{sample_requirement.id}|{sample_session.auditor_name}|{timestamp}"
         signature_hash = hashlib.sha256(data.encode()).hexdigest()
 
@@ -382,7 +382,7 @@ class TestSignOff:
 
         # First sign-off should trigger auto-start
         sample_session.status = AuditSessionStatusEnum.IN_PROGRESS
-        sample_session.started_at = datetime.utcnow()
+        sample_session.started_at = datetime.now(timezone.utc)
 
         assert sample_session.status == AuditSessionStatusEnum.IN_PROGRESS
 
@@ -390,7 +390,7 @@ class TestSignOff:
         """Updating an existing sign-off should work."""
         sample_signoff.result = AuditResultEnum.NON_COMPLIANT
         sample_signoff.notes = "Updated: needs improvement"
-        sample_signoff.updated_at = datetime.utcnow()
+        sample_signoff.updated_at = datetime.now(timezone.utc)
 
         assert sample_signoff.result == AuditResultEnum.NON_COMPLIANT
         assert "Updated" in sample_signoff.notes
@@ -423,7 +423,7 @@ class TestGetSignOff:
 
         # With signature
         sample_signoff.signature_hash = "abc123"
-        sample_signoff.signed_at = datetime.utcnow()
+        sample_signoff.signed_at = datetime.now(timezone.utc)
         sample_signoff.signed_by = "Test Auditor"
 
         assert sample_signoff.signature_hash == "abc123"

backend-compliance/compliance/tests/test_auto_risk_updater.py

@@ -4,7 +4,7 @@ Tests for the AutoRiskUpdater Service.
 Sprint 6: CI/CD Evidence Collection & Automatic Risk Updates (2026-01-18)
 """
 
-from datetime import datetime
+from datetime import datetime, timezone
 from unittest.mock import MagicMock
 
 from ..services.auto_risk_updater import (
@@ -188,7 +188,7 @@ class TestGenerateAlerts:
         scan_result = ScanResult(
             scan_type=ScanType.DEPENDENCY,
             tool="Trivy",
-            timestamp=datetime.utcnow(),
+            timestamp=datetime.now(timezone.utc),
             commit_sha="abc123",
             branch="main",
             control_id="SDLC-002",
@@ -209,7 +209,7 @@ class TestGenerateAlerts:
         scan_result = ScanResult(
             scan_type=ScanType.SAST,
             tool="Semgrep",
-            timestamp=datetime.utcnow(),
+            timestamp=datetime.now(timezone.utc),
             commit_sha="def456",
             branch="main",
             control_id="SDLC-001",
@@ -228,7 +228,7 @@ class TestGenerateAlerts:
         scan_result = ScanResult(
             scan_type=ScanType.CONTAINER,
             tool="Trivy",
-            timestamp=datetime.utcnow(),
+            timestamp=datetime.now(timezone.utc),
             commit_sha="ghi789",
             branch="main",
             control_id="SDLC-006",
@@ -247,7 +247,7 @@ class TestGenerateAlerts:
         scan_result = ScanResult(
             scan_type=ScanType.SAST,
             tool="Semgrep",
-            timestamp=datetime.utcnow(),
+            timestamp=datetime.now(timezone.utc),
             commit_sha="jkl012",
             branch="main",
             control_id="SDLC-001",
@@ -369,7 +369,7 @@ class TestScanResult:
         result = ScanResult(
             scan_type=ScanType.DEPENDENCY,
             tool="Trivy",
-            timestamp=datetime.utcnow(),
+            timestamp=datetime.now(timezone.utc),
             commit_sha="xyz789",
             branch="develop",
             control_id="SDLC-002",

backend-compliance/compliance/tests/test_compliance_routes.py

@@ -8,7 +8,7 @@ Run with: pytest compliance/tests/test_compliance_routes.py -v
 """
 
 import pytest
-from datetime import datetime
+from datetime import datetime, timezone
 from unittest.mock import MagicMock
 from uuid import uuid4
 
@@ -41,8 +41,8 @@ def sample_regulation():
         name="Datenschutz-Grundverordnung",
         full_name="Verordnung (EU) 2016/679",
         is_active=True,
-        created_at=datetime.utcnow(),
-        updated_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
+        updated_at=datetime.now(timezone.utc),
     )
 
 
@@ -57,8 +57,8 @@ def sample_requirement(sample_regulation):
         description="Personenbezogene Daten duerfen nur verarbeitet werden, wenn eine Rechtsgrundlage vorliegt.",
         priority=4,
         is_applicable=True,
-        created_at=datetime.utcnow(),
-        updated_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
+        updated_at=datetime.now(timezone.utc),
     )
 
 
@@ -74,8 +74,8 @@ def sample_ai_system():
         classification=AIClassificationEnum.UNCLASSIFIED,
         status=AISystemStatusEnum.DRAFT,
         obligations=[],
-        created_at=datetime.utcnow(),
-        updated_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
+        updated_at=datetime.now(timezone.utc),
     )
 
 
@@ -96,8 +96,8 @@ class TestCreateRequirement:
             description="Geeignete technische Massnahmen",
             priority=3,
             is_applicable=True,
-            created_at=datetime.utcnow(),
-            updated_at=datetime.utcnow(),
+            created_at=datetime.now(timezone.utc),
+            updated_at=datetime.now(timezone.utc),
         )
 
         assert req.regulation_id == sample_regulation.id
@@ -196,7 +196,7 @@ class TestUpdateRequirement:
     def test_update_audit_status_sets_audit_date(self, sample_requirement):
         """Updating audit_status should set last_audit_date."""
         sample_requirement.audit_status = "compliant"
-        sample_requirement.last_audit_date = datetime.utcnow()
+        sample_requirement.last_audit_date = datetime.now(timezone.utc)
 
         assert sample_requirement.audit_status == "compliant"
         assert sample_requirement.last_audit_date is not None
@@ -287,7 +287,7 @@ class TestAISystemCRUD:
 
     def test_update_ai_system_with_assessment(self, sample_ai_system):
         """After assessment, system should have assessment_date and result."""
-        sample_ai_system.assessment_date = datetime.utcnow()
+        sample_ai_system.assessment_date = datetime.now(timezone.utc)
         sample_ai_system.assessment_result = {
             "overall_risk": "high",
             "risk_factors": [{"factor": "education sector", "severity": "high"}],

backend-compliance/compliance/tests/test_isms_routes.py

@@ -15,7 +15,7 @@ Run with: pytest backend/compliance/tests/test_isms_routes.py -v
 """
 
 import pytest
-from datetime import datetime, date
+from datetime import datetime, date, timezone
 from unittest.mock import MagicMock
 from uuid import uuid4
 
@@ -56,7 +56,7 @@ def sample_scope():
         status=ApprovalStatusEnum.DRAFT,
         version="1.0",
         created_by="admin@breakpilot.de",
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -65,7 +65,7 @@ def sample_approved_scope(sample_scope):
     """Create an approved ISMS scope for testing."""
     sample_scope.status = ApprovalStatusEnum.APPROVED
     sample_scope.approved_by = "ceo@breakpilot.de"
-    sample_scope.approved_at = datetime.utcnow()
+    sample_scope.approved_at = datetime.now(timezone.utc)
     sample_scope.effective_date = date.today()
     sample_scope.review_date = date(date.today().year + 1, date.today().month, date.today().day)
     sample_scope.approval_signature = "sha256_signature_hash"
@@ -88,7 +88,7 @@ def sample_policy():
         authored_by="iso@breakpilot.de",
         status=ApprovalStatusEnum.DRAFT,
         version="1.0",
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -116,7 +116,7 @@ def sample_objective():
         related_controls=["OPS-003"],
         status="active",
         progress_percentage=0.0,
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -136,7 +136,7 @@ def sample_soa_entry():
         coverage_level="full",
         evidence_description="ISMS Policy v2.0, signed by CEO",
         version="1.0",
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -158,7 +158,7 @@ def sample_finding():
         identified_date=date.today(),
         due_date=date(2026, 3, 31),
         status=FindingStatusEnum.OPEN,
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -178,7 +178,7 @@ def sample_major_finding():
         identified_date=date.today(),
         due_date=date(2026, 2, 28),
         status=FindingStatusEnum.OPEN,
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -198,7 +198,7 @@ def sample_capa(sample_finding):
         planned_completion=date(2026, 2, 15),
         effectiveness_criteria="Document approved and distributed to audit team",
         status="planned",
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -219,7 +219,7 @@ def sample_management_review():
             {"name": "ISO", "role": "ISMS Manager"},
         ],
         status="draft",
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -239,7 +239,7 @@ def sample_internal_audit():
         lead_auditor="internal.auditor@breakpilot.de",
         audit_team=["internal.auditor@breakpilot.de", "qa@breakpilot.de"],
         status="planned",
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(timezone.utc),
     )
 
 
@@ -502,7 +502,7 @@ class TestISMSReadinessCheck:
         """Readiness check should identify potential major findings."""
         check = ISMSReadinessCheckDB(
             id=str(uuid4()),
-            check_date=datetime.utcnow(),
+            check_date=datetime.now(timezone.utc),
             triggered_by="admin@breakpilot.de",
             overall_status="not_ready",
             certification_possible=False,
@@ -532,7 +532,7 @@ class TestISMSReadinessCheck:
         """Readiness check should show status for each ISO chapter."""
         check = ISMSReadinessCheckDB(
             id=str(uuid4()),
-            check_date=datetime.utcnow(),
+            check_date=datetime.now(timezone.utc),
             triggered_by="admin@breakpilot.de",
             overall_status="ready",
             certification_possible=True,
@@ -606,7 +606,7 @@ class TestAuditTrail:
             entity_name="ISMS Scope v1.0",
             action="approve",
             performed_by="ceo@breakpilot.de",
-            performed_at=datetime.utcnow(),
+            performed_at=datetime.now(timezone.utc),
             checksum="sha256_hash",
         )
 
@@ -630,7 +630,7 @@ class TestAuditTrail:
             new_value="approved",
             change_summary="Policy approved by CEO",
             performed_by="ceo@breakpilot.de",
-            performed_at=datetime.utcnow(),
+            performed_at=datetime.now(timezone.utc),
             checksum="sha256_hash",
         )