LocalAuth

[TheUltDev]

• Persist authentication in memory for as long as possible to avoid extraneous login requests. (most likely via Service Worker)
• Database cleanup (when removing passkeys, we should delete associated databases)

[steida]

TODO: Refactor and redesign LocalAuth from scratch by requirements from Trezor. We have to allow multiple Evolu instances per one credential and allow multiple credentials. I suppose we can't avoid explicit login and storing encryption key in memory-only does not help much, we will see. Also, add an example we had in vitest example to app playground.