Building and electrical applications: measurements behind design choices

Electrical

The audit of src/noodl/apps/electrical (excluding modelica/ and thermal.py) for issue #22 S06 found no benchmark numbers, timings or implementation narratives in the sources. The code keeps the mathematics (MATPOWER case format and per-unit conventions, the DC power-flow linearisation, waveform phasor conventions) and the engine-parity facts it reproduces; there is nothing to move here.