Migrating from ostree to composefs backend

I don't think we have any reasonable, documented way to do this today. Just creating this as a tracker and a place to write down potential approaches and any known problems. We're going to need to be able to do this eventually, and selfishly right now I'm in a place where my laptop has migrated from ostree-based Silverblue => ostree-based custom bootc deployment and I would like to swap to the composefs backend but am also too lazy at the moment to back everything up and wipe to do a clean install.

Questa issue serve da tracker per la migrazione da un Silverblue basato su ostree o da un deployment bootc personalizzato a un backend composefs. Non vengono indicati file, test o punti di ingresso; inizia esaminando i possibili approcci e i problemi noti, mentre la procedura di migrazione e i relativi criteri di completamento devono ancora essere definiti.

Scritto dal modello di indicizzazione a partire dal testo della issue.