Jellyfin PDB Manager
The Jellyfin PodDisruptionBudget (PDB) Manager is a small go project that can run as sidecar along with Jellyfin and automatically configures the Jellyfin PDB to block or unblock depending on sessions that are watching something.
This simple construct integrates Jellyfin with Kubernetes allowing graceful handling of updates, making sure that draining of a node is blocked until you finished watching your show.
Limitations: this doesn't prevent deletion or updates of the Jellyfin Pods itself, it just prevents certain voluntary disruptions.