PI-DeepONet LFR Fuel-Pin Steady-State Dataset (v0.1) — 5000 Layer-1 cases + 30 OpenFOAM anchors

> Lead-cooled fast reactor (LFR) fuel-pin steady-state coupled neutronics > + thermal-hydraulics + mechanics + fission-gas-release dataset. > Contains 5 000 Layer-1 cases (reduced reference stack: python_ref + > analytic_diffusion + scikit_fem + Booth) and 30 OpenFOAM anchors > (chtMultiRegionSimpleFoam) sharing a 7-D Latin-Hypercube design space > and a common 16 × 20 (r, z) grid. Global energy conservation is > verified to better than 10⁻³ relative residual on every case. > Used as the training set for the PI-DeepONet surrogate model > described in the companion paper (DOI: TBD). > See README.md for the full HDF5 schema and parameter ranges.