Hello there, just giving a heads up on what happened (probably nobody cares, but for the clarity).

I changed my game from the .exe into browser playable. That's all the changes, so it is still the same version.

For more in dev?
I compiled SDL3 stuff from source as .a files
I linked them in the project which has the same code but different settings
I setup projects for it
I changed the code which runs the main loop to run it emscripten (new SDL3 callbacks) style.

And I am happy.

That's all, stay determined pals and make games!