[FEAT] smart-enter: add open_multi option

[greyxp1]

Neccesarry Preconditions

• I checked the update is compatible with the latst yazi version
• I have used the plugin successfully on my platform

I tested / have been using the plugin successfully on the following platforms

NixOS

I am able to package this plugin myself

• I am able to package this plugin myself

Avoiding Duplicates

• I checked existing open and closed issues and PRs to see if this is already in Progress

[greyxp1]

This would add a configuration option that allows passing all selected files to the system open command, rather than defaulting to only the hovered file. This is particularly useful when using Yazi as the file picker.