I create mod which reproduces background music, and i have 2 track(track_1.mp3 and track_2.mp3), when i install this mod in Opera and turned on background music, plays only first track, and the second track overlaps, not all of it, always when i use keyboard or mouse.
My manifest.json:

{
    "manifest_version": 3,
    "name": "S.T.A.L.K.E.R. & Metro",
    "description": "Mod for S.T.A.L.K.E.R. and Metro fans",
    "version": "1.1",
    "icons":
    {
        "1540": "icon_1540.png"
    },
    "developer":
    {
        "name": "Mandi_OS"
    },
    "mod":
    {
        "schema_version": 1,
        "payload":
        {	
            "background_music":
            [
                "music/track_1.mp3",
                "music/track_2.mp3"
            ],

            "wallpaper":
            {
                "dark":
                {   
		    "image": "wallpaper/wallpaper_1.jpg",
		    "text_color": "#FFFFFF",
                    "text_shadow": "#757575"
                },
		    "light":
                {   
	            "image": "wallpaper/wallpaper_1.jpg",
                    "text_color": "#FFFFFF",
                    "text_shadow": "#0B000E"
                }
	    }
        }
    }
}

Please tell me how i can fix that?

Please, tell me how i can do changing wallpapers(21) with Opera mod, i searched this in default mods(https://github.com/opera-gaming/gxmods/tree/main/mods) manifests, but vain.

I think it would be amazing to add site I want to sidebar, and optionally to context menu. For example I want to see my Steam quick, and don't open new window. Or if take AI's for example, I want to add my individual AI, for example Claude, or Gemini, or anything else.
And if talking about context menu, may more acces to code? For example:
"Use this text in %d", site_func
Where site_func is function(or function kit) from site I want to add in context. And same with images, videos etc.
Of course that's not very easy, but I think it's worth it!

I create mod which reproduces background music, and i have 2 track(track_1.mp3 and track_2.mp3), when i install this mod in Opera and turned on background music, plays only first track, and the second track overlaps, not all of it, always when i use keyboard or mouse.
My manifest.json:

{
    "manifest_version": 3,
    "name": "S.T.A.L.K.E.R. & Metro",
    "description": "Mod for S.T.A.L.K.E.R. and Metro fans",
    "version": "1.1",
    "icons":
    {
        "1540": "icon_1540.png"
    },
    "developer":
    {
        "name": "Mandi_OS"
    },
    "mod":
    {
        "schema_version": 1,
        "payload":
        {	
            "background_music":
            [
                "music/track_1.mp3",
                "music/track_2.mp3"
            ],

            "wallpaper":
            {
                "dark":
                {   
		    "image": "wallpaper/wallpaper_1.jpg",
		    "text_color": "#FFFFFF",
                    "text_shadow": "#757575"
                },
		    "light":
                {   
	            "image": "wallpaper/wallpaper_1.jpg",
                    "text_color": "#FFFFFF",
                    "text_shadow": "#0B000E"
                }
	    }
        }
    }
}

Please tell me how i can fix that?

After 30 minutes of Packing the mod (extension), the files in the mod's root folder are deleted, except for one mp3 file(there were 2 before packing),
Is this normal? And if not, how i can fix that?

Please, tell me how i can do changing wallpapers(21) with Opera mod, i searched this in default mods(https://github.com/opera-gaming/gxmods/tree/main/mods) manifests, but vain.