feat(tui): add dual-pane SFTP file browser

[vybraan]

Implements the initial SFTP file transfer view for #8.

This adds dual-pane file browser with:

• local and remote directory navigation
• upload from local to remote
• download from remote to local

[lfaoro]

should add ctrl+s to the list of commands expanded with ? pressing ctrl+s again should toggle back

[lfaoro]

would it be hard to have the ability to select multiple files to transfer using spacebar for selection ?

[lfaoro]

should add ctrl+s to readme, and update changelog with the new feature

[vybraan]

should add ctrl+s to readme, and update changelog with the new feature

sure,

would it be hard to have the ability to select multiple files to transfer via ?

i dont believe so, will check it.

[vybraan]

would it be hard to have the ability to select multiple files to transfer using spacebar for selection ?

@lfaoro I think for now i'm going to keep it imp for multiple individual files but excluding the folders, i guess it can become messy pretty quick if i happen to do for thousands of folders and nested folders. So to transfer files in a dir you'd have to select all files inside and transfer them. what do think?