Add Migration Squashing / Schema Baseline Support

[KevinSkayro]

We're preparing our Payload project for production, and we've accumulated a large number of development migrations. Before launching, we want to squash these into a single baseline migration that represents our current schema — then begin tracking new schema changes with clean migration history post-launch.

This is a common step in other frameworks:

Laravel has php artisan schema:dump

Prisma supports migrate diff + resolve --applied

These allow teams to discard noisy dev migrations and start from a clean baseline when going live.
Here a reference of what I mean in Laravel: https://laravel.com/docs/12.x/migrations#squashing-migrations

Would be great to see a built-in CLI command like payload migrate:squash or schema:baseline to help with this!

I think this could be a nice feature for Payload, is this something the Payload Team considered?

If this already exists, feel free to drop it, I could not find anything on it.