install to-filesystem overwrites SSH host keys and SSH user keys and password

When I do a ```bootc switch``` or ```bootc update```` my SSH host keys and SSH user keys and password are preserved. But when I used ```bootc install to-filesystem``` they are lost.

When I connect to the same IP address after ```install to-filesystem``` SSH complains about the host keys having changed. In addition, the contents of /home, the SSH username, password have all been lost.

This behavior seems unexpectedly different, and surprising to me. Why does ```bootc switch``` keep the contents of /etc (and somehow merge it) and ```bootc install``` discards it? Ditto for other directories.

Inizia tracciando il percorso di bootc install to-filesystem e confrontandolo con bootc switch e bootc update, concentrandoti su come vengono gestiti /etc, /home, le chiavi SSH, gli utenti e le password. Riproduci l’installazione, esamina il filesystem risultante e definisci come completamento la conservazione dello stato di sistema previsto senza modificare il comportamento consolidato di switch o update.

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