feat: Add orm for Tools and clean up Tool logic (#1935)

letta/orm/mixins.py

@@ -55,7 +55,6 @@ class OrganizationMixin(Base):
 
     __abstract__ = True
 
-    # Changed _organization_id to store string (still a valid UUID4 string)
     _organization_id: Mapped[str] = mapped_column(String, ForeignKey("organization._id"))
 
     @property
@@ -65,3 +64,19 @@ class OrganizationMixin(Base):
     @organization_id.setter
     def organization_id(self, value: str) -> None:
         _relation_setter(self, "organization", value)
+
+
+class UserMixin(Base):
+    """Mixin for models that belong to a user."""
+
+    __abstract__ = True
+
+    _user_id: Mapped[str] = mapped_column(String, ForeignKey("user._id"))
+
+    @property
+    def user_id(self) -> str:
+        return _relation_getter(self, "user")
+
+    @user_id.setter
+    def user_id(self, value: str) -> None:
+        _relation_setter(self, "user", value)