- dmd 2.112.1
- ldc 1.43.0 beta1
- dub 1.41.0
- dtools 2.112.1

- odd hilighting issue ... must result from my org config, but "fix"
  makes things easier for me.

- revert to using GCC14: (current) GCC 15
  introduced nullptr in its headers, and DMD's
  ImportC parser needs update to handle it,
  monitor and update

- (nix ldc overlay, minor comsetic)