udev rules for camera hotplug support

[jsnapoli1]

Description

Create udev rules so the camera device node is created with correct permissions and a stable name on hotplug, ensuring the daemon can always find the camera without root privileges.

Definition of Done

[ ] udev rule creates a symlink /dev/pagespeak-cam-raw pointing to the actual /dev/videoX device
[ ] Device node permissions allow the daemon user to open without root
[ ] Unplugging and re-plugging the camera re-creates the symlink correctly
[ ] Rule is installed via a Yocto recipe under meta-pagespeak/recipes-config/
[ ] Tested with at least 2 different USB webcam models (if available) to confirm UVC matching works