Provide a way to rotate the session password

[tobiasdiez]

It is advised that one rotates every security-related credential on some time interval (and of course after a breach). To make this easier, there should be a bultin functionality to specify a second password that is used to decrypt old sessions (while the primary password is used to en/decrypt new sessions).

[kleinpetr]

Great idea 👌

I think it's more a question of https://github.com/unjs/h3 where the actual logic of encryption takes place :)