Migrate from legacy supabase client to Mobula SDK DB client

[NBMSacha]

Mobula App codebase is still using the supabase client, which might be misleading for users trying to learn the codebase or check code examples from the API.

Mobula SDK now allows DB access: https://docs.mobula.io/sdk/database

Might be worth switching from supabase to the wrapper provided in the SDK.