Generic discovery of Logitech USB Video Class (UVC) webcams.
Mice and keyboards speak Logitech's proprietary HID++ (over a Bolt/Unifying
receiver or directly) — see the openlogi-hid crate. Webcams don't: every
Logitech camera (StreamCam, Brio, C920, C922, C270, C930e, …) is a standard
UVC device and enumerates the same way. So detection keys off the USB vendor
id (0x046d) rather than any per-model quirk — plug in any Logitech
camera and it's recognised, with no model table to maintain.
macOS has the full backend (AVFoundation capture + IOKit UVC controls);
Windows matches it with Media Foundation capture and DirectShow controls;
Linux uses V4L2 for both, through the kernel's uvcvideo driver. Other
platforms return an empty list.