fix(ci): fix alembic DB import and golangci-lint version

- Move Base to app/models/base.py so alembic env.py can import it
  without triggering engine creation (which connects to hardcoded DB)
- Update all 13 models to import Base from app.models.base
- Pin golangci-lint to latest (supports Go 1.25)

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

backend/app/models/alert.py

@@ -16,7 +16,7 @@ from sqlalchemy import (
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
-from app.database import Base
+from app.models.base import Base
 
 
 class AlertRule(Base):

backend/app/models/api_key.py

@@ -8,7 +8,7 @@ from sqlalchemy import DateTime, ForeignKey, Text, func
 from sqlalchemy.dialects.postgresql import JSONB, UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
-from app.database import Base
+from app.models.base import Base
 
 
 class ApiKey(Base):

backend/app/models/audit_log.py

@@ -8,7 +8,7 @@ from sqlalchemy import DateTime, ForeignKey, String, Text, func
 from sqlalchemy.dialects.postgresql import JSONB, UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
-from app.database import Base
+from app.models.base import Base
 
 
 class AuditLog(Base):

backend/app/models/base.py

@@ -0,0 +1,9 @@
+"""SQLAlchemy declarative base — importable without triggering engine creation."""
+
+from sqlalchemy.orm import DeclarativeBase
+
+
+class Base(DeclarativeBase):
+    """Base class for all SQLAlchemy ORM models."""
+
+    pass

backend/app/models/certificate.py

@@ -12,7 +12,7 @@ from sqlalchemy import DateTime, ForeignKey, LargeBinary, String, Text, func
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
-from app.database import Base
+from app.models.base import Base
 
 
 class CertificateAuthority(Base):

backend/app/models/config_backup.py

@@ -18,7 +18,7 @@ from sqlalchemy import (
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
-from app.database import Base
+from app.models.base import Base
 
 
 class ConfigBackupRun(Base):

backend/app/models/config_template.py

@@ -14,7 +14,7 @@ from sqlalchemy import (
 from sqlalchemy.dialects.postgresql import JSON, UUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
-from app.database import Base
+from app.models.base import Base
 
 
 class ConfigTemplate(Base):

backend/app/models/device.py

@@ -18,7 +18,7 @@ from sqlalchemy import (
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
-from app.database import Base
+from app.models.base import Base
 
 
 class DeviceStatus(str, Enum):

backend/app/models/firmware.py

@@ -15,7 +15,7 @@ from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
 from sqlalchemy import ForeignKey
 
-from app.database import Base
+from app.models.base import Base
 
 
 class FirmwareVersion(Base):

backend/app/models/key_set.py

@@ -7,7 +7,7 @@ from sqlalchemy import DateTime, ForeignKey, Integer, LargeBinary, Text, func
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
-from app.database import Base
+from app.models.base import Base
 
 
 class UserKeySet(Base):

backend/app/models/maintenance_window.py

@@ -11,7 +11,7 @@ from sqlalchemy import Boolean, DateTime, ForeignKey, Text, VARCHAR, func
 from sqlalchemy.dialects.postgresql import JSONB, UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
-from app.database import Base
+from app.models.base import Base
 
 
 class MaintenanceWindow(Base):

backend/app/models/tenant.py

@@ -7,7 +7,7 @@ from sqlalchemy import DateTime, LargeBinary, Integer, String, Text, func
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
-from app.database import Base
+from app.models.base import Base
 
 
 class Tenant(Base):

backend/app/models/user.py

@@ -8,7 +8,7 @@ from sqlalchemy import Boolean, DateTime, ForeignKey, LargeBinary, SmallInteger,
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
-from app.database import Base
+from app.models.base import Base
 
 
 class UserRole(str, Enum):

backend/app/models/vpn.py

@@ -8,7 +8,7 @@ from sqlalchemy import Boolean, DateTime, ForeignKey, Integer, LargeBinary, Stri
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
-from app.database import Base
+from app.models.base import Base
 
 
 class VpnConfig(Base):