flask-admin multiple sessions issue

Just a short app to reproduce multiple sessions with sqlalhemy

flask-admin issue for more context: 2831

It is not a project, nor a fork

It is used only to prepare reproducable environment.

Steps to reproduce

• clone it and run with uv run main.py
• try to create and "Art" and it will throw error that Team already exist in different session
• uncomment either form_extra_fields or form_args in ArtsView and it works fine
• Try to edit Art (add extra team, not name), Unique validator fails
• Change from USE_CUSTOM_EQUATION = False to USE_CUSTOM_EQUATION = True, editing works
• if MODE = "anythong except lite" it will run full sqlalchemy and creating/editing works without changing anything