Purge history to prevent secret leakage

[luanpotter]

Is your feature request related to a problem? Please describe.

Sorry if I am just being dumb, I took a look at GitHub and at the man-pages for this, and I could not find any relevant threads to poke at.

Currently, I could not find a simple way to purge the entire clipboard history, across all clipboards. I can use cb clear to clear the current value, but the history remains set in stone.

Describe the solution you'd like

I would propose to add a cb purge [x] command, where if x is not specified, purges all entries in the history, and if it is, purge the last x entries. Purge would completely obliterate any references to the value and remove it from history. Of course, the command would ask for a confirmation before doing an irreversible operation.

Describe alternatives you've considered

I eventually found out data is stored under /run/user/x/Clipboard, so I was able to "purge" by deleting it. But that is not very intuitive nor have I found it document anywhere, and it also lacks easy fine controls of what to purge.

Additional context

This is particularly useful if you end up copying say a password or secret by mistake, that you then want to purge from the system.

Again, I am so sorry if I am missing anything from the doc or that should be obivous.