[feature request] sync options via firefox profile

Hello,

## Context :
I have my firefox profile sync with 3 firefox instances. I configure wallabager on a computer, and it was working perfectly!
So now, I switch from computer and try to save an article. I got no error alert, but it's like if the extension try to save but without succeeding to do it. Then I realize that I haven't made any configuration to this firefox instance. ;(
I import the configuration file from the preferences, then it has working perfectly directly ;)

## Possible solution:
* provide an alert for this specific case (I suppose that when it's not configured, there is an alert ?)
* use the password manager of firefox to save the tokens and profil to let it sync to other computers

thanks

The issue names no files, tests, or entry points. Start by tracing the preferences import and article-save behavior for an unconfigured Firefox instance, then determine whether completion means an explicit alert, Firefox password-manager storage and syncing, or both.

Written by the indexing model from the issue text.