[ryoku] hyprland: add wallpaper theme sync for keyboard RGB

[Shreyas-cpu]

Summary

Adds `ryoku-cmd-keyboard-rgb` to synchronize laptop keyboard backlights (ASUS ROG, TUF, Zephyrus via `asusctl` / sysfs, and OpenRGB devices) to the active

wallpaper Material palette.

Details

- **Palette Extraction & Boost**: Reads active Material You tone `70`/`80` from `~/.cache/ryoku/material-colors.json` or `~/.cache/ryoku/colors.json`, boosting

HSV saturation for vivid, readable keyboard backlighting.
- Hardware Integration:
- Queries asusctl led-mode -c <hex> (ASUS Aura laptops).
- Falls back to direct sysfs control (/sys/class/leds/asus::kbd_backlight/kbd_rgb_mode).
- Broadcasts to ryoku-hub lighting accent <hex> for peripheral ecosystem sync.
- Event Hooks:
- Hooked into ryoku/shell/matugen/config.toml (post_hook) to instantly transition colors when wallpapers change.
- Hooked into ryoku/hyprland/modules/autostart.lua on compositor startup.

### Testing & Verification
- Validated with `bin/ryoku-dev-scan-slop` (clean).
- Validated with `bin/ryoku-dev-verify-delivery` (clean).
- Commit message conforms to `[area]` subject prefix and trailer rules.
- Tested on ASUS hardware with Hyprland + Matugen.

Note: New: Synchronize laptop keyboard backlight with wallpaper theme palette

[neur0map]

thanks for putting this together. keyboard-follows-wallpaper already ships end to end: the daemon pushes the accent to keyboard lighting on every palette change and both compositors restore it at login, all gated behind the Lighting opt-in in the Hub. this script would write the keyboard hardware outside that gate and duplicate the same push, so we're going to keep the existing path instead of merging. the feature you're after is already there, just turn Lighting on and adopt the keyboard in the Hub. sorry for the drive-by close, and thanks again.