3.2.0

• DCA bug fixes:

  • dca.duong_cum — fixed linspace-inversion bug where cumulative volume integrated over a descending axis for t < 0.001 (small-t inputs) and returned a negative value. Lower bound of the integration is now min(0.001, t * 0.001) so the grid is always ascending.
  • dca.forecast — now validates dt > 0, t_end > 0 and uptime in (0, 1] at entry with clear ValueError messages. Previously dt = 0 raised an opaque ZeroDivisionError and out-of-range uptime was silently accepted.

• Rachford-Rice solver consolidation: simtools.rr_solver is now a thin wrapper that delegates to the canonical pyrestoolbox.brine._lib_vle_engine.rr_solver (Nielsen & Lia 2022). Removes ~100 lines of duplicated iterative code plus the dead ensure_numpy_array helper. Inputs validated for length/sum before delegation; behaviour is preserved (EPS_T=1e-15, max_iter=100).

• Rust Sechenov fallback guard: src/vle/mod.rs::flash_tp_rust no longer silently substitutes its S&W Eq 8 ks fallback when a caller passes all-ones gamma with salinity > 0. The caller-supplied gamma is now always trusted, eliminating any risk that Python framework='proposed' calls bypass the specialised Dubessy/Akinfiev/Li/Mao-Duan/Duan-Sun ks models. calc_equilibrium_rust retains the S&W Eq 8 path but now carries a prominent doc warning. Python path unchanged (Python always passes the correct gamma).

• Convergence flag on CO2_Brine_Mixture: New .converged attribute on the class. True after a successful Spycher-Pruess fugacity iteration, False when the 100-iteration limit is hit (matching the existing RuntimeWarning). Lets downstream callers detect non-convergence programmatically.

• sensitivity.tornado robustness: Raises ValueError if base_result is not finite (NaN/Inf), and if any ranges[param] has lo > hi. Previously returned nan or inf sensitivities that silently corrupted tornado plots.

• layer module dedup: Five copies of the EXP/LANG dispatch (B-clamp, flow-fraction evaluation) consolidated into three private helpers (_clamp_b, _b_max, _flow_fraction_at_x). No behaviour change.

• recommend module docstrings: sg on recommend_gas_methods and well_type on recommend_vlp_method are currently unused by the decision logic. Docstrings now flag them as reserved for future rules. Signatures preserved for backward compatibility.

• 701 validation tests (up from 696 in 3.1.5).