Opening a PR as this is quite a heavy structural change.
Basic idea:
switch to more modern JS with import / export in the backend
remove all individual imports in the manifest.json and trick it to load a background html page
use webpack to insert bundled background javascript in the production background html page (similar fashion as the front)
nice bonuses: we can defer code duplication during the build process which means we don't have code duplication anymore in the source code (it only appears in the dist and should be minimal anwyays) and better minification of code
other point: ENV variable is define inside webpack, that way we can add more logic in conf/env.js to support debug env etc.
Opening a PR as this is quite a heavy structural change.
Basic idea: