Like others mentioned file structure is the most important. In addition you can also grab the AniDB plugin and set it as the primary metadata source in Jellyfin. (I had it for quite a while so dunno how much difference it makes compared to TVDB, but from experience I practically never had wrong metadata on an anime)

I have been using Authentik for several years now, works great with k8s. Not sure about the difference between Keycloak and Authentik tho (feature vise)