fix: resolve backend CI errors for MyPy and Ruff

- Fix PyPNGImage save() method call (remove format parameter)
- Fix return type annotation in is_mfa_required()
- Remove unused imports and reorder imports
- Update timezone imports from timezone to UTC
- Fix test assertions formatting

Frontend CI fixes to follow in subsequent commit

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

api/controllers/console/auth/login.py

@@ -14,8 +14,6 @@ from controllers.console.auth.error import (
     EmailPasswordLoginLimitError,
     InvalidEmailError,
     InvalidTokenError,
-    MFARequiredError,
-    MFATokenRequiredError,
 )
 from controllers.console.error import (
     AccountBannedError,

api/controllers/console/auth/mfa.py

@@ -1,12 +1,8 @@
 from typing import cast
 
 import flask_login
-from flask import request
 from flask_restful import Resource, reqparse
 
-from controllers.console.auth.error import (
-    TokenValidationError,
-)
 from controllers.console.wraps import account_initialization_required
 from libs.login import login_required
 from models.account import Account

api/controllers/console/workspace/account.py

@@ -389,7 +389,8 @@ api.add_resource(EducationAutoCompleteApi, "/account/education/autocomplete")
 # api.add_resource(AccountEmailVerifyApi, '/account/email-verify')
 
 # MFA endpoints
-from controllers.console.auth.mfa import MFASetupInitApi, MFASetupCompleteApi, MFADisableApi, MFAStatusApi
+from controllers.console.auth.mfa import MFADisableApi, MFASetupCompleteApi, MFASetupInitApi, MFAStatusApi
+
 api.add_resource(MFAStatusApi, "/account/mfa/status")
 api.add_resource(MFASetupInitApi, "/account/mfa/setup")
 api.add_resource(MFASetupCompleteApi, "/account/mfa/setup/complete")

api/services/mfa_service.py

@@ -2,13 +2,10 @@ import base64
 import io
 import json
 import secrets
-from datetime import datetime, timezone
+from datetime import UTC, datetime
-from typing import Optional
 
 import pyotp
 import qrcode
-from sqlalchemy import and_
-from sqlalchemy.orm import Session
 
 from models.account import Account, AccountMFASettings
 from models.engine import db
@@ -53,7 +50,7 @@ class MFAService:
         
         # Convert to base64
         buffer = io.BytesIO()
-        img.save(buffer, format='PNG')
+        img.save(buffer)
         img_str = base64.b64encode(buffer.getvalue()).decode()
         
         return f"data:image/png;base64,{img_str}"
@@ -120,7 +117,7 @@ class MFAService:
         # Enable MFA
         mfa_settings.enabled = True
         mfa_settings.backup_codes = json.dumps(backup_codes)
-        mfa_settings.setup_at = datetime.now(timezone.utc)
+        mfa_settings.setup_at = datetime.now(UTC)
         
         db.session.commit()
         
@@ -176,7 +173,7 @@ class MFAService:
     def is_mfa_required(account: Account) -> bool:
         """Check if MFA is required for this account."""
         mfa_settings = db.session.query(AccountMFASettings).filter_by(account_id=account.id).first()
-        return mfa_settings and mfa_settings.enabled and mfa_settings.secret is not None
+        return bool(mfa_settings and mfa_settings.enabled and mfa_settings.secret is not None)
 
     @staticmethod
     def authenticate_with_mfa(account: Account, token: str) -> bool:

api/tests/integration_tests/controllers/console/auth/test_login_mfa_integration.py

@@ -1,14 +1,8 @@
 import json
 import sys
-import pytest
 from unittest.mock import Mock, patch
-from datetime import datetime
 
 from flask import Flask
-from flask_restful import Api
-
-from controllers.console.auth.login import LoginApi
-from models.account import Account, AccountMFASettings
 
 
 class TestLoginMFAIntegration:
@@ -292,8 +286,8 @@ class TestMFAEndToEndFlow:
     @patch('services.mfa_service.db.session')
     def test_complete_mfa_setup_flow(self, mock_session, mock_gen_codes, mock_verify, mock_gen_qr, mock_gen_secret):
         """Test complete MFA setup flow from init to completion."""
-        from services.mfa_service import MFAService
         from models.account import Account
+        from services.mfa_service import MFAService
 
         # Mock account
         account = Mock(spec=Account)

api/tests/integration_tests/controllers/console/auth/test_mfa_endpoints.py

@@ -1,7 +1,8 @@
-import pytest
+from datetime import UTC, datetime
-from datetime import datetime, timezone
 from unittest.mock import patch
 
+import pytest
+
 from services.account_service import AccountService
 from services.mfa_service import MFAService
 
@@ -71,7 +72,7 @@ class TestMFAEndpoints:
         with patch.object(MFAService, 'setup_mfa') as mock_setup:
             mock_setup.return_value = {
                 "backup_codes": ["CODE1", "CODE2", "CODE3", "CODE4", "CODE5", "CODE6", "CODE7", "CODE8"],
-                "setup_at": datetime(2024, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
+                "setup_at": datetime(2024, 1, 1, 0, 0, 0, tzinfo=UTC)
             }
             
             response = test_client.post(
@@ -97,7 +98,8 @@ class TestMFAEndpoints:
         
         assert response.status_code == 400
         data = response.json
-        assert "message" in data and "TOTP token is required" in data["message"]
+        assert "message" in data
+        assert "TOTP token is required" in data["message"]
     
     def test_mfa_setup_complete_invalid_token(self, test_client, setup_account, auth_header):
         """Test MFA setup completion with invalid token."""

api/tests/integration_tests/controllers/console/auth/test_mfa_simple.py

@@ -1,7 +1,5 @@
-import json
 from unittest import mock
 
-from models.account import Account
 from services.mfa_service import MFAService
 
 
@@ -12,7 +10,7 @@ class TestMFASimpleIntegration:
         """Test MFA setup flow end-to-end."""
         # Step 1: Check initial MFA status
         response = test_client.get(
-            f"/console/api/account/mfa/status",
+            "/console/api/account/mfa/status",
             headers=auth_header
         )
         assert response.status_code == 200
@@ -21,7 +19,7 @@ class TestMFASimpleIntegration:
         
         # Step 2: Initialize MFA setup
         response = test_client.post(
-            f"/console/api/account/mfa/setup",
+            "/console/api/account/mfa/setup",
             headers=auth_header
         )
         assert response.status_code == 200
@@ -33,7 +31,7 @@ class TestMFASimpleIntegration:
         # Step 3: Complete MFA setup with mocked TOTP
         with mock.patch.object(MFAService, 'verify_totp', return_value=True):
             response = test_client.post(
-                f"/console/api/account/mfa/setup/complete",
+                "/console/api/account/mfa/setup/complete",
                 headers=auth_header,
                 json={"totp_token": "123456"}
             )
@@ -44,7 +42,7 @@ class TestMFASimpleIntegration:
         
         # Step 4: Verify MFA is now enabled
         response = test_client.get(
-            f"/console/api/account/mfa/status",
+            "/console/api/account/mfa/status",
             headers=auth_header
         )
         assert response.status_code == 200
@@ -55,7 +53,7 @@ class TestMFASimpleIntegration:
         """Test MFA disable flow."""
         # First check MFA status and disable if already enabled
         response = test_client.get(
-            f"/console/api/account/mfa/status",
+            "/console/api/account/mfa/status",
             headers=auth_header
         )
         assert response.status_code == 200
@@ -65,7 +63,7 @@ class TestMFASimpleIntegration:
             # MFA is already enabled, disable it first with mocked password verification
             with mock.patch('libs.password.compare_password', return_value=True):
                 response = test_client.post(
-                    f"/console/api/account/mfa/disable",
+                    "/console/api/account/mfa/disable",
                     headers=auth_header,
                     json={"password": "any_password"}  # Password doesn't matter, it's mocked
                 )
@@ -75,14 +73,14 @@ class TestMFASimpleIntegration:
         with mock.patch.object(MFAService, 'verify_totp', return_value=True):
             # Initialize setup
             response = test_client.post(
-                f"/console/api/account/mfa/setup",
+                "/console/api/account/mfa/setup",
                 headers=auth_header
             )
             assert response.status_code == 200
             
             # Complete setup
             response = test_client.post(
-                f"/console/api/account/mfa/setup/complete",
+                "/console/api/account/mfa/setup/complete",
                 headers=auth_header,
                 json={"totp_token": "123456"}
             )
@@ -91,7 +89,7 @@ class TestMFASimpleIntegration:
         # Now disable MFA with mocked password verification
         with mock.patch('libs.password.compare_password', return_value=True):
             response = test_client.post(
-                f"/console/api/account/mfa/disable",
+                "/console/api/account/mfa/disable",
                 headers=auth_header,
                 json={"password": "any_password"}  # Password doesn't matter, it's mocked
             )
@@ -101,7 +99,7 @@ class TestMFASimpleIntegration:
         
         # Verify MFA is disabled
         response = test_client.get(
-            f"/console/api/account/mfa/status",
+            "/console/api/account/mfa/status",
             headers=auth_header
         )
         assert response.status_code == 200

api/tests/unit_tests/services/test_mfa_service.py

@@ -1,9 +1,7 @@
 import json
 import unittest
+from datetime import datetime
 from unittest.mock import Mock, patch
-from datetime import datetime, timezone
-
-import pytest
 
 from models.account import Account, AccountMFASettings
 from services.mfa_service import MFAService