Agree on how we want to manually handle fixture data locally

[ryanolee]

Currently we handle migrations using the firebase cli locally (Under firebase/emulator_data using the export:firebase script which is later committed). This gets loaded into the app on each start up in the start:firebase script.

This issue aims to confirm if we want to save the state on exiting so that local development data is not lost when doing so (--export-on-exit). See: https://mukhtharcm.com/firebase-emulator-persist-data/ .

Or if we are ok with manually exporting the firebase data using export:firebase when we want to export things locally

[LodenH16]

I think persisting local emulator data is a great idea and will help development a lot.

We should also create some mock data to seed the emulator when it initializes. We could also have a command to wipe and re-seed the emulator in case anything gets too borked to repair, I know I would make use of that 😅

This also is an excellent opportunity to commit to a "schema" for how headmate data will be stored, useful for #9.