Allow users to Export individual files to a VM

[ninavizz]

Problem

Users are increasingly needing to work with files in other VMs, more than handing them off to another human on a thumb drive. Today, most are using thumb drives as their intermediary to accomplish that ends—which is clunky.

Solution

Build into the Client's UI an option for users to choose if they'd like to export files to another VM within Qubes, or to a USB stick.

MVP and Enhancement paths, are shown below—with a future state vision, being to additionally curate a sanitization VM for users to fast-track sanitization.

[ninavizz]

A first pass at this! First screen is a basic flow chart (that for some reason I don't know I made go backwards?), and then there's a giant pink button to enter the prototype.

1. Menu shows a future-state that includes export to qube and export to usb. Qubes OS is moving towards removal of "VM" in user-facing nomenclature, hence use of "qube" there. Whatever goes in the MVP of Export Source, I'd like to see elegantly scale up to include export to qube.
2. There is also a screen with multiple menu naming schemas and icon options, both for the MVP and when Export is extended to support Export to VM.

https://www.figma.com/proto/YejZGCIGZikX55LDcfvcYY/Client-%E2%89%A5-Q4-2021?page-id=259%3A78578&node-id=294%3A39103&viewport=241%2C48%2C1&scaling=min-zoom&starting-point-node-id=276%3A38672