[BUG] Motherboard fails to power off / hangs on shutdown (ASRock H410M-HDV)

### Pre-flight checklist

- [x] I have searched existing issues and this is not a duplicate.
- [x] I have read the [Contributing Guidelines](https://github.com/CachyOS/linux-cachyos/blob/master/CONTRIBUTING.md).
- [x] I have verified the issue is reproducible with the latest available CachyOS kernel.
- [x] I have tried to reproduce the issue on Arch Linux's `linux` kernel.

### Upstream / vanilla kernel check

I have not tested with a vanilla/upstream kernel

### Kernel variant

linux-cachyos (EEVDF, Clang)

### System information (cachyos-bugreport.sh)

```text
https://paste.cachyos.org/p/9f0e2a6.log
```

### Manual system information (if cachyos-bugreport.sh is unavailable)

```text

```

### Bug description

**NOTE:** @ptr1337 requested me on Discord to open this tracking issue here. (I have not tested a completely vanilla Arch kernel, but the issue persists on linux-cachyos-lts v6.18.36-1).

I have a persistent issue where my system fails to power off cleanly on shutdown. The display goes black and the OS unmounts, but the fans, CPU cooler, and LEDs stay spinning infinitely.

Also, warm reboots (restarting the system) almost always trigger a cold reboot (full power cut and POST). When this happens, the motherboard often gets stuck in a boot loop/failing to POST (motherboard clicking) for about 40 minutes until I do a full power drain.

This does not happen on Windows. Our analysis of the systemd journal logs (journalctl -b -2) shows that systemd successfully unmounts all Btrfs filesystems cleanly (including the /var/cache subvolume on 7.1.1-2). The freeze happens at the very end when the kernel tries to signal the motherboard to cut power.

### Steps to reproduce

1. Boot into CachyOS with default kernel command line.
2. Click "Shutdown" or "Reboot" in Hyprland/KDE.
3. The screen goes black, but the motherboard power remains fully active (fans, LEDs spinning). If rebooting, the system fully power-cycles and can get stuck failing to POST.

There is a 50% chance this happens, or it just simply works.

### Expected behavior

The motherboard should cleanly cut power on shutdown (fans stop spinning). Warm reboots should restart the system without a full hardware power-cycle.

### Actual behavior

Monitor signal is lost, but the PC chassis remains fully powered. Reboots force a physical power cut and starts by itself, therefore sometimes not starting up anymore due to motherboard safety mechanisms untill i fully drain the power from it.

### Logs / stack traces

```text
Here are three notable errors found in my boot logs that point to power state and USB handoff conflicts:

1. Realtek Ethernet card ASPM conflict (blocked by BIOS):
[ 8.672986] r8169 0000:02:00.0: can't disable ASPM; OS doesn't have ASPM control

2. Broken SATA Link Power Management (Seagate HDD):
[ 0.121047] ata4.00: Model 'ST1000DM010-2EP102', rev 'CC43', applying quirks: nolpm
[ 0.121047] ata4.00: LPM support broken, forcing max_power

3. Unstable USB connection with MAD68 Hall-Effect keyboard (might be hanging the xHCI controller on power-off):
[ 121.231296] usb 1-2: USB disconnect, device number 8
[ 125.171214] usb usb1-port2: Cannot enable. Maybe the USB cable is bad?
[ 125.526387] usb 1-2: device descriptor read/64, error -71
Product: MAD68
```

### Additional system information

Desktop Environment: Hyprland (UWSM) / KDE Plasma
Motherboard: ASRock H410M-HDV (UEFI BIOS v1.30, Date: 08/10/2020)
Memory: 16GB RAM (running at 2666MHz due to CPU limits)
GPU: MSI NVIDIA GTX 1650 (Wayland / open drivers v610.43.02)
Storage: GOODRAM SSD (sda), ADATA SSD (sdb), Seagate HDD (sdc)

I am planning to test the following kernel command line parameters to see if forcing PCIe control and lowering SATA LPM helps:
pcie_aspm=force ahci.mobile_lpm_policy=1 acpi_osi="Windows 2015"

Along with setting BIOS Legacy USB Support to "UEFI Setup Only".