chore: Clean up repository code and structure

- Removed commented packages: cura, parsec-bin, bottles, stremio, gimp, calibre
- Removed commented code: Java enable, low-latency kernel, ROCm packages, bridges
- Removed trailing whitespace across multiple files
- Fixed typo: Depreciated -> Deprecated in networking
- Removed unused desktop/gnome.nix module (not referenced)
- Removed systems/common-headless.nix (duplicates common.nix)
- Removed nixpkgs.config.allowBroken setting
- Added result, *.swp, *~ to .gitignore
- Removed .clinerules file (deprecated, info in docs/agents.md)
- Updated docs/agents.md changelog with cleanup details

desktop/3dprinting.nix

@@ -3,7 +3,6 @@
 {
 
 environment.systemPackages = with pkgs; [
-#  cura
   freecad
   super-slicer
   openscad