* tweak the way we store schedule information and just keep `schedule_day` and `schedule_hour` directly as their own columns.
* add a function for `retrieve-scheduled-channels` which makes it easy to get a list of the channels that should be triggered given a day & hour as input.

GET /api/database/form_input shouldn't require auth

provide information about our `:engines` through our main MetabaseSettings which simplifies some things and removes the need for a /api/database/form_input endpoint.

Make `setup-db` take db details as an argument

fussing around a bit with a more complete persistence layer implementation and really simplifying api endpoints.

wrap our main create/update persistence methods for pulses in a transaction so that everything is atomic and we don't get partially modified db records in the event of an error.