How to organize releases in Mercurial?

Question

JavaScript

Good afternoon!
help me figure out the mess in my head and the mercurial or tell me how the following can be most successfully organized:
I want to make three branches for the project:
- local - local development
- dev - intermediate build of the project for the test server
- production - final build of the project (js / css minification , removing fish, etc.) - for a combat server
That is, as I imagine:
in local - sources and tasks for building in gulpgile.js (ver.1 - without minification, without image compression, etc. - for quick builds, but with live-reload)
in dev and production - src should not be, there should be only a built project (or not?)
somewhere else there should be gulpfile.js (ver.2) - with tasks for building the production version
what I tried to do:
1) I added the files of the finished project to ignore in local, otherwise changes to these files are constantly registered - it seemed to me superfluous during development, I wanted only changes in the source codes to be displayed in the commits. But then I ran into a problem - these ignored files cannot be pushed into other branches, which is logical = \
2) then I tried to go in from the other side - the same sources are in local and dev, but different ignored gulpfile.js: in dev gulpfile with production build tasks. There are other problems here: a) sources get into production, b) these sources can be edited in any branch - either colleagues forget to switch, or "it's business for 5 seconds - I'll quickly fix it in production" - not good.
as a result, the head is a complete mess =\
I would also like that in dev and production files could be changed only as a result of the merge, but not by hand (for point 2.b.) - is there such a possibility? Or am I overthinking?
what scheme do you want ideally:
development in local -> built the project (gulpfile-ver.1) -> pushed it to dev (without sources - just a finished build) -> if everything is ok, then built the project (gulpfile-ver.2) and pushed into production, otherwise all over again.