DD-FRC reproducibility models

Companion preprints by Joseph Finberg, Laurelin Technologies Inc.

Files:
- eta_rec_model.py: static first-principles recovery ledger.
- pulse_twin.py: full-cycle time-domain recovery model.
- pulse_twin_mc.py: Monte Carlo uncertainty propagation (seed 20260815).
- viability_o2.py: zero-dimensional net-energy viability model.
- field_target_20T.py: audited 20 T design-basis calculations; no third-party packages.
- make_figures.py: figure generator for the qualification paper.
- field_target_20T.txt: byte-stable default output from field_target_20T.py.

Run field_target_20T.py with Python 3.11 or newer; it uses the standard library only.
The remaining models use NumPy and/or SciPy. make_figures.py additionally uses
Matplotlib and schemdraw. Each file contains its equations, assumptions, and run notes.
The 0.0775896 T, 10 kJ circuit models are a recovery-bench result and do not constitute
a 20 T magnet or conductor demonstration.
