PYTHON_CUSTOM_SCRIPTS_3DE4 is not being appended

Is there an existing issue for this?

• I have searched the existing issues and added correct labels.

Description

Current Behavior

https://github.com/ynput/ayon-equalizer/blob/51cc2747cacb081ec4193d0a5f0581a655b5ab74/client/ayon_equalizer/addon.py#L43C1-L47C30

        startup_path = os.path.join(EQUALIZER_HOST_DIR, "startup")
        if "PYTHON_CUSTOM_SCRIPTS_3DE4" in env:
            startup_path = os.path.join(
                env["PYTHON_CUSTOM_SCRIPTS_3DE4"],
                startup_path)

If PYTHON_CUSTOM_SCRIPTS_3DE4 is present in env it's being joined to addon's path, which results in wrong path.

custom = "/my/custom/3de/script"
startup_path = "/path/ayon-equalizer/client/ayon_equalizer/startup"
startup_path = os.path.join(custom, startup_path)
print (startup_path) # /path/ayon-equalizer/client/ayon_equalizer/startup

Expected Behavior

From 3DE Doc:
3DE4PYTHON_CUSTOM_SCRIPTS_3DE4
A colon separated list of directories to look for additional python scripts (Windows: list is separated by semicolons).

os.path.join could be flipped to os.pathsep.join or any other solution which will result in /custom/path:/ayon-addon/path

Steps To Reproduce:

No response

Additional context:

Version

Latest version of ayon-equalizer

What platform were you running when you found the bug?

Linux - Rocky9

Relevant log output:

Start in client/ayon_equalizer/addon.py around lines 43-47 and review how PYTHON_CUSTOM_SCRIPTS_3DE4 is combined with the add-on startup path. Reproduce the behavior on Linux, then verify that the resulting value preserves both directories using the platform’s expected path-list separator, including the documented Windows form.