dist(AppImage): unable to run models after restarting the app

[gucio321]

Describe the bug

Downloading extensions creates venv (for example Modly/extensions/hunyuan3d-mini/venv).
This venv is probably created witha python instance shipped with the app.
The default python venv creates a symlink to the parent python executable.
however, as the executable is mounted in a temporary directory, which is different every run, after the 2nd run it fails to run the old venv.

Simple fix would be to enforce copying files while venv creation with --copies

Steps to reproduce

1. download AppImage
2. download any model
3. close and re-open app
4. try to generate anything (will get error 400). Try to hit repair on a model - will see python crash caused by not existing file

Modly version

0.4.0

Operating system

Arch linux

Screenshots & logs

No response

Confirmation

• I have searched existing issues and this has not been reported yet.
• I can reproduce this on the latest version of Modly.