Hello! I think that you should add separate CToolsEditor module and add all Editor stuff in it. Here is the code that can be used in .uplugin to keep thengs separated (main things in CNavigation module and Editor things in CNavigationEditor module)
{
...
"Plugins": [
{
"Name": "CExtCore",
"Enabled": true
}
],
"Modules": [
{
"Name": "CNavigation",
"Type": "Runtime",
"LoadingPhase": "Default"
},
{
"Name": "CNavigationEditor",
"Type": "Editor",
"LoadingPhase": "PostEngineInit"
}
]
}