fix: fix orm_exc.DetachedInstanceError (#34904)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/services/account_service.py

@@ -9,7 +9,8 @@ from typing import Any, TypedDict, cast
 
 from pydantic import BaseModel, TypeAdapter
 from sqlalchemy import delete, func, select, update
-from sqlalchemy.orm import Session, sessionmaker
+
+from core.db.session_factory import session_factory
 
 
 class InvitationData(TypedDict):
@@ -800,19 +801,19 @@ class AccountService:
         return token
 
     @staticmethod
-    def get_account_by_email_with_case_fallback(email: str, session: Session | None = None) -> Account | None:
+    def get_account_by_email_with_case_fallback(email: str) -> Account | None:
         """
         Retrieve an account by email and fall back to the lowercase email if the original lookup fails.
 
         This keeps backward compatibility for older records that stored uppercase emails while the
         rest of the system gradually normalizes new inputs.
         """
-        query_session = session or db.session
-        account = query_session.execute(select(Account).filter_by(email=email)).scalar_one_or_none()
-        if account or email == email.lower():
-            return account
+        with session_factory.create_session() as session:
+            account = session.execute(select(Account).filter_by(email=email)).scalar_one_or_none()
+            if account or email == email.lower():
+                return account
 
-        return query_session.execute(select(Account).filter_by(email=email.lower())).scalar_one_or_none()
+            return session.execute(select(Account).filter_by(email=email.lower())).scalar_one_or_none()
 
     @classmethod
     def get_email_code_login_data(cls, token: str) -> dict[str, Any] | None:
@@ -1516,8 +1517,7 @@ class RegisterService:
 
         check_workspace_member_invite_permission(tenant.id)
 
-        with sessionmaker(db.engine, expire_on_commit=False).begin() as session:
-            account = AccountService.get_account_by_email_with_case_fallback(email, session=session)
+        account = AccountService.get_account_by_email_with_case_fallback(email)
 
         if not account:
             TenantService.check_member_permission(tenant, inviter, None, "add")