FR: reduce QR code image size by using ts.net for URLs

### What are you trying to do?

Terminals are sometimes small. The 80x25 console of a VM, for example. The 29x29 QR code with its generous margins can easily overflow such small displays, making it hard to scan.

### How should we solve this?

HTTPS://XYZ.TLD/12+3:AB.C

This URL encodes to a 21x21 code using the the QR alphanumeric character set at 4.5 bits per char. The 48 bit login code is reduced from 12 hex digits to 9 base41 symbols (A-Z0-9 and 5 more chars from the QR alphanumeric set such as +-*.: )

The domain can be up to 7 chars (ABCD.CC or XYZ.TLD). It should not be expensive or hard to get (as I imagine ts.net probably was).

### What is the impact of not solving this?

_No response_

### Anything else?

Uppercase url schema and dns names are RFC compliant and I am not aware of any device that has problems with opening these urls. I have encountered uppercase URLs like these “in the wild”