0.6.0 - the console gets out of the way

Everything you actually watch a machine for is on the picture. Everything else should be one click away and then gone again. This release is a rearrangement around that idea.
- The firmware version is a badge in the status bar. It shows a dot when a newer build is published, and its outline fills like a progress ring while an update installs. Click it and the whole firmware panel opens.
- Live diagnostics - chip temperature, memory, uptime, ESP-IDF version - left the Settings page and became a rail button that already shows the temperature and a rough uptime.
- The guessed target OS got its own rail button too, next to it. Click it and you see the raw USB fingerprint it guessed from.
- The image list, the choice of medium and uploads moved out of Settings and into the Virtual media panel, where you were already looking.
- The rail and its panels now open on the same side, and a setting flips the whole unit left or right.