Chore/infra ci asan docs

[Paramveersingh-S]

Hey Ulrich!
Here's what I've added in this PR:

1. AddressSanitizer (ASan) Support I added a USE_ASAN option in src/CMakeLists.txt. When enabled, this compiles the project with AddressSanitizer. Since we do a lot of heavy lifting with memory allocations in the rendering paths (especially with the recent GLU tessellator changes), this will automatically catch memory leaks and use-after-free bugs during testing.
2. Cleaned up the CI Matrix I noticed that .github/workflows/ubuntu.yml was setting up a matrix for 4 different ARM/AMD platforms, but since it wasn't using a cross-compiler or QEMU, it was basically just doing the exact same amd64 build 4 times redundantly. I fixed this and refactored both the Ubuntu and macOS workflows so that they now run a clean matrix testing against gtk4: [ON, OFF] and asan: [ON, OFF]. This ensures every commit gets validated properly across UI backends and memory safety checks!
3. Automated Docs Deployment Since we both worked on adding Doxygen and man pages recently, I added a quick .github/workflows/docs.yml action. It automatically builds the Doxygen HTML docs and deploys them straight to GitHub Pages whenever code is pushed to main.
   Let me know what you think, and if you have any feedback or tweaks you'd like me to make before we merge this!

[schwicke]

Thanks for the contribution!

About ASan, there may be some overlap with #52 which adds support for this as well, and fixes issues which have been detected with it so far.

I'll try to have a look at all this asap.