The previous footer credit ("MIT License · Powered by avr8js &
wokwi-elements") was wrong twice over: velxio is AGPLv3 (with a
commercial license available), and the project now ships much more
than the two libraries it singled out (rp2040js, eecircuit-engine,
QEMU, ESP-IDF, arduino-cli, Monaco editor, ...).
Replace it with a one-paragraph About Velxio that sits at the bottom
of the landing page, mirrors what the blog footer shows at
velxio.dev/blog/, and correctly states the AGPLv3 license.
Widen .footer-copy to max-width: 680px so the longer copy has room
to breathe and breaks across two lines on desktop.