fix: Add reconstructor to initialize transient fields

Introduces a reconstructor method to ensure that transient fields
such as 'role' and '_current_tenant' are initialized upon loading
an instance of the Account model. This change improves the
object's state consistency, especially when instances are
reloaded from the database, ensuring these fields are set
to 'None' by default.

Signed-off-by: -LAN- <laipz8200@outlook.com>

api/models/account.py

@@ -4,7 +4,7 @@ from typing import Optional, cast
 
 from flask_login import UserMixin  # type: ignore
 from sqlalchemy import func
-from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.orm import Mapped, mapped_column, reconstructor
 
 from models.base import Base
 
@@ -81,8 +81,6 @@ class AccountStatus(enum.StrEnum):
 
 
 class Account(UserMixin, Base):
-    role: Optional["TenantAccountRole"] = None
-    _current_tenant: Optional["Tenant"] = None
     __tablename__ = "accounts"
     __table_args__ = (db.PrimaryKeyConstraint("id", name="account_pkey"), db.Index("account_email_idx", "email"))
 
@@ -103,6 +101,11 @@ class Account(UserMixin, Base):
     created_at = db.Column(db.DateTime, nullable=False, server_default=func.current_timestamp())
     updated_at = db.Column(db.DateTime, nullable=False, server_default=func.current_timestamp())
 
+    @reconstructor
+    def init_on_load(self):
+        self.role: Optional[TenantAccountRole] = None
+        self._current_tenant: Optional[Tenant] = None
+
     @property
     def is_password_set(self):
         return self.password is not None