repo + branch: https://github.com/WelcometoMyGarden/welcometomygarden/tree/v3/sveltekit
Using the layout from SvelteKit
https://kit.svelte.dev/docs/routing#layout
And using the svelte onMount
https://svelte.dev/tutorial/onmount
In the onMount we initialize Firebase (including Firebase Auth)
https://github.com/WelcometoMyGarden/welcometomygarden/blob/4c12e0bddc5814f3a506c1f430d3eb1952bb9266/src/routes/%2Blayout.svelte#L48
(the Initialze function)
https://github.com/WelcometoMyGarden/welcometomygarden/blob/4c12e0bddc5814f3a506c1f430d3eb1952bb9266/src/lib/api/firebase.ts#L31
Now that I am describing this, I think there probably should be a more elegant method for this.