test: update service tests for fixture and API changes

Updates to work with refactored fixtures (no expunge):
- Re-query entities when modifying state in tests
- Remove assertions on expunged object properties

Auth service tests:
- Update to use email_or_username field instead of username

Admin service tests:
- Fix statistics test to use stats_service module
- Remove vendor_name filter test (field removed)
- Update import job assertions

Inventory/Marketplace/Stats/Vendor service tests:
- Refactor to work with attached session objects
- Update assertions for changed response formats
- Improve test isolation and cleanup

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

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

tests/unit/services/test_auth_service.py

@@ -72,7 +72,7 @@ class TestAuthService:
     def test_login_user_success(self, db, test_user):
         """Test successful user login"""
         user_credentials = UserLogin(
-            username=test_user.username, password="testpass123"
+            email_or_username=test_user.username, password="testpass123"
         )
 
         result = self.service.login_user(db, user_credentials)
@@ -87,7 +87,9 @@ class TestAuthService:
 
     def test_login_user_wrong_username(self, db):
         """Test login fails with wrong username"""
-        user_credentials = UserLogin(username="nonexistentuser", password="testpass123")
+        user_credentials = UserLogin(
+            email_or_username="nonexistentuser", password="testpass123"
+        )
 
         with pytest.raises(InvalidCredentialsException) as exc_info:
             self.service.login_user(db, user_credentials)
@@ -100,7 +102,7 @@ class TestAuthService:
     def test_login_user_wrong_password(self, db, test_user):
         """Test login fails with wrong password"""
         user_credentials = UserLogin(
-            username=test_user.username, password="wrongpassword"
+            email_or_username=test_user.username, password="wrongpassword"
         )
 
         with pytest.raises(InvalidCredentialsException) as exc_info:
@@ -113,12 +115,15 @@ class TestAuthService:
 
     def test_login_user_inactive_user(self, db, test_user):
         """Test login fails for inactive user"""
-        # Deactivate user
-        test_user.is_active = False
+        from models.database.user import User
+
+        # Re-query user and deactivate
+        user = db.query(User).filter(User.id == test_user.id).first()
+        user.is_active = False
         db.commit()
 
         user_credentials = UserLogin(
-            username=test_user.username, password="testpass123"
+            email_or_username=test_user.username, password="testpass123"
         )
 
         with pytest.raises(UserNotActiveException) as exc_info:
@@ -130,7 +135,7 @@ class TestAuthService:
         assert "User account is not active" in exception.message
 
         # Reactivate for cleanup
-        test_user.is_active = True
+        user.is_active = True
         db.commit()
 
     def test_get_user_by_email(self, db, test_user):
@@ -285,7 +290,9 @@ class TestAuthService:
 
     def test_login_user_database_error(self, db_with_error):
         """Test user login handles database errors"""
-        user_credentials = UserLogin(username="testuser", password="password123")
+        user_credentials = UserLogin(
+            email_or_username="testuser", password="password123"
+        )
 
         with pytest.raises(InvalidCredentialsException):
             self.service.login_user(db_with_error, user_credentials)