Additional Drivers tab hangs indefinitely with TypeError: cannot pickle 'SoftwarePropertiesGtk' object on AnduinOS 2.0.0

When opening Software & Updates and switching to the Additional Drivers tab, the application never finishes searching for available drivers and remains stuck on:

"Searching for available drivers..."

Launching the application from the terminal reveals the following exception:

Exception in thread Thread-1 (detect_drivers):
...
TypeError: cannot pickle 'SoftwarePropertiesGtk' object

The traceback points to:

softwareproperties/gtk/SoftwarePropertiesGtk.py

and Python's multiprocessing module:

multiprocessing.popen_forkserver
TypeError: cannot pickle 'SoftwarePropertiesGtk' object
System Information
OS: AnduinOS 2.0.0
Base: Ubuntu Resolute (26.04)
Python: 3.14
Package:
anduinos-software-properties-gtk 2.0.0+0.120-2+resolute-addon
anduinos-software-properties-common 2.0.0+0.120-2+resolute-addon
Diagnostics

ubuntu-drivers devices returns immediately without errors:

ubuntu-drivers devices

APT is healthy:

sudo apt update
sudo apt --fix-broken install
sudo dpkg --configure -a

No broken packages or repository issues were found.

Hardware drivers are correctly loaded:

Intel Iris Xe Graphics (i915)
Intel Wi-Fi 6 AX201 (iwlwifi)
Intel Ethernet (e1000e)
Intel Audio (snd_hda_intel)

There is no NVIDIA or Broadcom hardware requiring proprietary drivers.

Steps to Reproduce
Open Software & Updates.
Navigate to the Additional Drivers tab.
The interface remains indefinitely on "Searching for available drivers...".
Running software-properties-gtk from a terminal produces the traceback above.
Expected Behavior

The Additional Drivers tab should either:

Display available proprietary drivers, or
Inform the user that no additional drivers are available.

Instead, it hangs indefinitely because of the Python exception.

Additional Notes

This appears to be related to Python 3.14's multiprocessing behavior, where SoftwarePropertiesGtk cannot be pickled when spawning the background driver detection process.

Start in softwareproperties/gtk/SoftwarePropertiesGtk.py and inspect the Additional Drivers search path around the multiprocessing traceback. Reproduce with software-properties-gtk, compare with ubuntu-drivers devices, and verify that the Additional Drivers tab finishes by showing available drivers or reporting that none are available without a TypeError.