Validate raw camera ranges and percent mapping with a real PTZ Pro 2

[jochenwezel]

The CLI supports --mode percent and --mode raw, and cam-device-info reports raw min/max/default/step/current where the backend can read it.

Open validation tasks:

• confirm raw min/max/default/step for zoom, pan, and tilt on Logitech PTZ Pro 2
• confirm percent-to-raw mapping is intuitive for absolute commands
• confirm relative percent deltas are visible and bounded correctly
• confirm guided test scripts use practical raw test values

Related commits:

• 0819532 Add camera device info command
• 2551bc1 Add explicit value modes for CLI moves
• d74dc4b Improve camera info and selection syntax
• 6457ad0 Add cross-platform metadata config and camera test scripts

[jochenwezel]

Additional related commit: 17f470e Document CLI syntax and expand camera tests. The guided test scripts now cover absolute/relative and percent/raw command variants with visible raw movement defaults.