fix: use residual stopping for FEAST eigenanalysis

src/fesa/solvers/eigen/mkl_feast_eigen_solver.cpp

@@ -174,7 +174,7 @@ void SetControls(std::array<MKL_INT, 128>& fpm, const bool count) {
   fpm[2] = 12;
   fpm[3] = 20;
   fpm[4] = 1;
-  fpm[5] = 1;
+  fpm[5] = 0;  // Trace convergence alone can leave individual pairs inaccurate.
   fpm[13] = 0;
   fpm[26] = 1;
   fpm[27] = 1;