thliebig/openEMS ? reverse-engineered prompt

Build me a free and open source electromagnetic field solver that can run finite difference time domain simulations in 3D, with support for both Cartesian and cylindrical grids. I want a C++ core that can handle things like absorbing boundaries, TFSF excitation, lumped RLC parts, dispersive materials, near field to far field output, and SAR calculations.

Please also include a simple command line program, plus Python and Octave or Matlab friendly interfaces for setting up and running simulations. It should be usable as a simulation engine with clear install and build steps, and it should produce field dumps in common formats like HDF5 and VTK.

Make it feel ready for real use, with a few example tutorials or smoke tests so I can verify the build works. If you need to check current dependency or build details, look up the latest docs online first.