[Bug]: System instability: Random freezes and hard crashes during gaming/browsing on 7900 XTX / Ryzen 9 7900X (Updated new error logs)

### Kernel

6.18.19-1-cachyos-lts

### Desktop Environment / Window Manager

KDE Plasma

### CPU

AMD Ryzen 9 7900X

### GPU / Driver

AMD Radeon RX 7900 XTX (0x1002:0x744C:0xC8)

### Description

I recently migrated from Windows to CachyOS. I’ve been experiencing persistent system crashes. On the standard CachyOS kernel, the system would completely freeze after about an hour of gaming, requiring a hard reset (holding the power button).

After switching to CachyOS LTS, the issue became less frequent and changed behavior: instead of a total crash, the system "locks up," cuts Bluetooth connection to my headset, and then wakes up or shows the Power/Session menu after pressing a key.

Troubleshooting already performed:

- Thermal Limits: Set CPU thermal limit to 85°C in BIOS (Liquid temp was around 40°C, idle CPU at 27°C).

- GPU Undervolt: Attempted undervolting the 7900 XTX to rule out PSU spikes (850W Corsair RM850x).

- Stress Testing: Ran a 45-minute stress test without any crashes, yet the system crashed later during light web browsing.

- Physical: Swapped power outlets and checked cables. The PC is only 3 months old.

System Specs:

- GPU: ASUS TUF AMD Radeon RX 7900 XTX OC

- CPU: AMD Ryzen 9 7900X

- RAM: 32GB (2x16GB) ADATA XPG Lancer RGB DDR5-6000 CL30

- Motherboard: MSI MAG B650 TOMAHAWK WIFI

- PSU: Corsair RM850x (850W)

- Cooling: NZXT Kraken Elite 360mm AIO

Attachments:
I have attached my current `cachyos-bugreport.sh output`. I will provide a second report generated immediately after the next crash occurs. Also including screenshots of my GPU undervolt settings for review.

https://paste.cachyos.org/p/89150b6.log

### Steps to Reproduce

1. Boot into CachyOS (issue occurred on both standard and LTS kernels, though less frequent on LTS).
2. Launch any high-demand game (e.g., AAA titles) or perform standard web browsing.
3. System typically runs for approximately 60 minutes.
4. Observe sudden system lock-up or total freeze.

### Expected Behavior

The system should remain stable under load and during idle/browsing tasks without requiring a hard reset. Bluetooth connectivity to peripherals (headset) should remain consistent, and the CPU/GPU should manage power transitions without triggering a session crash or freezing the UI.

### Actual Behavior

- On Standard Kernel: The system completely freezes. No mouse or keyboard input is registered. A hard reset (holding the power button) is the only way to recover.

- On LTS Kernel: The system "soft-locks." The screen may freeze, Bluetooth connection to the headset is dropped, and the system eventually recovers only after a keypress, which often brings up the Power/Session menu (Shutdown/Restart/Suspend).

- Symptoms: Even with a CPU thermal limit of 85°C and a stable 850W PSU, the system fails to maintain uptime despite passing 45-minute synthetic stress tests.

### Logs / Error Messages

https://paste.cachyos.org/p/89150b6.log

### Additional Context

_No response_