Each export now writes a small <model>.ts.pt.meta.json so the native side
(tp_dnn.cpp / CuasDnnLocal, pieces 3-4) reads the model's params from a bundled
sidecar instead of hardcoding them — single source of truth.
  L1: {N, P, vr, out_ch, velocity_mode, vmax}
  L2: {ch_hidden, vmax, grid, ch_in}
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>