Record gravity relift work before descent rejection

libmeanfield/interface/solver/newton_numerics.cppm

@@ -72,6 +72,8 @@ export namespace mean_field::solver::nonlinear {
 
     struct NumericalStrategyDiagnostics final {
         int polynomialChecks{0};
+        // Nonzero repair proposals include directions later rejected by a
+        // descent check; this measures repair activity, not accepted steps.
         int directionRepairs{0};
         double lastRepairFraction{0.0};
         double lastMeritDirectionalDerivative{0.0};