Add the supabase setup for setting up role based access.

- [x] Figure out how and add the SQL Scripts to the codebase.
- [ ] Research strategies for implementing role-based access.
- [ ] Build a general purpose role-based access system that can be easily removed.

Start by reviewing the SQL scripts already added to the codebase and research strategies for role-based access in Supabase. Define the general-purpose system's scope and removal criteria before implementation; done means the SQL setup and role-based access behavior are documented and tested against those criteria.

索引モデルが issue の本文から書いたものです。