Add I2C-HID keyboard RGB support and fix power limit controls

[utajum]

I2C-HID support (FA608PP and similar TUF models):

• Add HidrawHelper: native /dev/hidraw scanner via ioctl that finds
  ASUS keyboards on any bus (USB, I2C, SPI), bypassing HidSharp's
  USB-only limitation
• Add I2C-HID fallback in AsusHid: when HidSharp finds no USB AURA
  device, fall back to HidrawHelper for write and SetFeature operations
• Fix Aura._isACPI: revert to simple static bool matching Windows
  behavior — always send both HID and sysfs commands for TUF models
• Add AURA init handshake and auto-apply on startup in MainWindow
• Add I2C-HID udev rule using uevent grep for vendor ID matching
• Add HidrawHelper and kbd_rgb diagnostics

Power limit (PPT) fixes:

• Fix PL1/PL2 slider values not persisting to config across restarts
• Add "Auto-apply power limits on mode change" checkbox
• Add fPPT (fast boost) slider, hidden when ppt_fppt sysfs is absent
• Wire fPPT into ModeControl.AutoPower() for auto-apply on mode switch

Upstream sync:

• Remove G615LR from IsStrixLimitedRGB() (upstream 29e34cb3)
• Update .upstream-last-checked to d9f4a602

[github-actions]

Build Artifacts

Built from commit dae37a4 — Download from Actions run

Artifact	Description
ghelper	Native AOT binary
native-libs	libSkiaSharp.so + libHarfBuzzSharp.so
appimage	GHelper-x86_64.AppImage (all-in-one)

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# Option 1: AppImage (easiest)
chmod +x GHelper-x86_64.AppImage
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