Add per-key backlight off support and fix scroll lock indicator

[Lord-Memester]

Description

Added support for turning backlight off per-key.
Fixed typos.
Fixed implementation of scroll lock indicator.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[Lord-Memester]

Also notable:

In the main.js for the keychron web configurator tool, line 91171 is as follows:

                    return [w.r, w.g, w.b].some(m => m > 30) || (w[b] = Math.max(30, w[b])),

and performing a local override with the following minor change to that same line

                    return [w.r, w.g, w.b].some(m => m > 30) || (w[b] = Math.max(0, w[b])),

allows users to set hex #000000 for keys, which is what is required to disable them per-key.

[CalcProgrammer1]

The Apply Global Brightness screws with per-key color values as is, I would recommend either just doing away with the global V entirely in per key mode or multiplying the key specific V by the global V.

[cyatarow]

Thank you!
I bought a C3 Pro 8K, but I was confused because I couldn't select specific keys to "turn off" their RGB lighting in the per-key settings.
Modifying per_key_rgb.c as you suggested did the trick.

Could someone from the official Keychron team please merge this?

[cyatarow]

Thank you for removing the restriction

[CalcProgrammer1]

I made a merge request that fixes the per-key backlight brightness correctly by scaling the per-key value by global brightness, not just allowing full bright vs. off. This allows for proper RGB to HSV conversion for externally driven effects as well as dimmed values from Keychron Launcher, which the implementation provided in this MR does not properly handle.

See my MR here #492

[Lord-Memester]

I made a merge request that fixes the per-key backlight brightness correctly by scaling the per-key value by global brightness, not just allowing full bright vs. off. This allows for proper RGB to HSV conversion for externally driven effects as well as dimmed values from Keychron Launcher, which the implementation provided in this MR does not properly handle.

See my MR here #492

@CalcProgrammer1

I'm too busy to do a check of my own at the moment, but if your changes don't break any of my changes and do satisfy the requests of others who have commented on this PR, I'll merge your changes into mine. Would that be acceptable?