Feature: Backup Persistent Storage to make Clones

[BenWestgate]

https://tails.net/doc/persistent_storage/backup/index.en.html

Previously Bails had custom code to create backup USBs without a restart. That code was submitted to Tails and now Tails offers the same functionality making it redundant.

The new tool provided Tails needs to be tested so that I can guide and remind users to make backups of their Bails USB to preserve their wallet meta data and blockchain.

As well as to make clones.

[BenWestgate]

• Backup Tails walkthru (similar to setup Persistent Storage guidance)
• SIMPLE Reminder system for backups (the old ones are unnecessarily complex)
• Clone Tails walkthru (includes shell commands to prevent private data from copying unencrypted to the Friend's USB stick.)
• Clone Tails autostart (Introduce Bails to the new user on their first Run)
• Recovery Tool to get your encrypted wallet back from a friend's Cloned Bails USB. Ideally initiated by the friend

[BenWestgate]

Since a regular reminder system will be added by Tails this summer, lets only remind them to backup when they have reached 100% IBD and have not yet made a backup. This should persist restarts until a backup is successful.

[BenWestgate]

More explanation of the Cloning feature:

...clones would have a much simpler setup:

1. welcome them to Bails
2. possibly change a temporary passphrase if they didn’t write a strong one down while in their friend’s Tails session.
3. most likely the autostart script begins reencrypting the Persistent Storage in background here. (Another Tails open issue)
4. the autostart deletes itself so it behaves like a normal Bails installation from then on.
5. Launch bails-wallet so they can make a wallet.

[BenWestgate]

Limiting the scope of this issue to just the clones and reducing priority to medium.

This must be tackled after #81.