History storage for multiple accounts
Scli can be run with different --usernames (accounts / phone numbers), but maintains a single history file in ~/.local/share/scli/history. This jumbles histories from different accounts together.
One solution is to put the account-specific data (history, attachments) in sub-directories: ~/.local/share/scli/+123456789, etc.
Additional enhancement: implement per-account config files.
This should be in addition to --config-file, so that the right file is automatically checked based on the account's phone number.
Related: signal-cli saves attachments for all accounts in the same dir, https://github.com/AsamK/signal-cli/issues/298#issuecomment-912973504