Excessive CPU Usage when no game is running

I'm noting an issue with fossilize_replay doesn't properly exit after a game has closed down, it'll peg the CPU usage to 100% on 2 cores on Linux, I'll have played a game for a couple hours maybe and quit the game, only to come back later to find CPU usage is still excessively high, because I can hear the fans ramped up more than they should be when not running a game or running any computationally intensive applications. I can see it's usage in htop having CPU utilization being at 100%, I can see it has 2 threads running the same thing with shadow processes, that even if you kill one of them, it doesn't kill the other and has to be killed separately. I feel this might need a kill script after a game has exited that looks for fossilize_replay running to kill it.

Possible related issues: #247 , #84

Computer Information:
Manufacturer: ASUSTeK COMPUTER INC.
Model: PRIME Z270-A
Form Factor: Desktop
No Touch Input Detected
Processor Information:
CPU Vendor: GenuineIntel
CPU Brand: Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz
CPU Family: 0x6
CPU Model: 0x9e
CPU Stepping: 0x9
CPU Type: 0x0
Speed: 4500 MHz
8 logical processors
4 physical processors
Hyper-threading: Supported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Unsupported
SSE41: Supported
SSE42: Supported
AES: Supported
AVX: Supported
AVX2: Supported
AVX512F: Unsupported
AVX512PF: Unsupported
AVX512ER: Unsupported
AVX512CD: Unsupported
AVX512VNNI: Unsupported
SHA: Unsupported
CMPXCHG16B: Supported
LAHF/SAHF: Supported
PrefetchW: Unsupported
BMI1: Supported
BMI2: Supported
F16C: Supported
FMA: Supported
Operating System Version:
"Manjaro Linux" (64 bit)
Kernel Name: Linux
Kernel Version: 6.15.9-2-MANJARO
X Server Vendor: The X.Org Foundation
X Server Release: 12401008
X Window Manager: KWin
Steam Runtime Version: steam-runtime_1.0.20250519.130917
Client Information:
Version: 1751405894
Browser GPU Acceleration Status: Enabled
Browser Canvas: Enabled
Browser Canvas out-of-process rasterization: Enabled
Browser Direct Rendering Display Compositor: Disabled
Browser Compositing: Enabled
Browser Multiple Raster Threads: Enabled
Browser OpenGL: Enabled
Browser Rasterization: Enabled
Browser Raw Draw: Disabled
Browser Skia Graphite: Disabled
Browser Video Decode: Enabled
Browser Video Encode: Disabled
Browser Vulkan: Disabled
Browser WebGL: Enabled
Browser WebGL2: Enabled
Browser WebGPU: Disabled
Browser WebNN: Disabled
Video Card:
Driver: NVIDIA Corporation NVIDIA GeForce RTX 3070/PCIe/SSE2
Driver Version: 4.6.0 NVIDIA 575.64.05
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 143 Hz
VendorID: 0x10de
DeviceID: 0x2488
Revision Not Detected
Number of Monitors: 1
Number of Logical Video Cards: 1
Primary Display Resolution: 2560 x 1440
Desktop Resolution: 2560 x 1440
Primary Display Size: 23.50" x 13.23" (26.97" diag), 59.7cm x 33.6cm (68.5cm diag)
Primary VRAM: 8192 MB
Sound card:
Audio device: Realtek ALC1220
Memory:
RAM: 31773 Mb
VR Hardware:
VR Headset: None detected
Miscellaneous:
UI Language: English
LANG: en_AU.UTF-8
Total Hard Disk Space Available: 1876389 MB
Largest Free Hard Disk Block: 981510 MB
Storage:
Number of SSDs: 4
SSD sizes: 4000G,2000G,2000G,525G
Number of HDDs: 0
Number of removable drives: 0

Start with the fossilize_replay process lifecycle on Linux and compare the behavior described here with related issues #247 and #84. Reproduce the high CPU usage after closing a game, then trace why the process and its worker threads remain active; done means fossilize_replay exits without sustained CPU usage after the game closes.