Your own text on the licence plate, more natural plates

Added

plate=text with plate_text=… writes your own text on the licence plate, e.g. ?plate=text&plate_text=DRIVE%202026: up to 10 characters — letters, digits, spaces and - . & — kept exactly as you send them, centred and sized to the plate.
It sits on the plate the same way in every view, in the light of the scene, like the plate logo.
The option is enabled per key. /api/me shows it as addon.plate_text, and /api/options lists text under plate when your key has it. Without it, plate=text is ignored with errornote O31 (or 403 without fallbacks).
A missing or too long plate_text, other characters, or plate_text without plate=text return 400.

plate=blank, plate=logo and plate=text keep the light that falls on the plate in the image: shading, edges and gloss stay, and the plate is as bright as the scene allows. Until now the plate was lifted to an even white and looked lit from within, most visibly next to a shaded bumper.
The logo on the plate is shaded the same way, so it no longer looks brighter than the car around it.
plate=text looks like a real plate: a thin dark border with rounded corners, room between text and border, and a slight shadow under the raised letters.

In some angled views the plate logo was drawn twice with a small offset, which made its edges look doubled. Each plate now gets the logo once.
Images with plate=blank or plate=logo that you requested before are recalculated with the new look on the next request; image links you already hold keep working.