Enforce floating arithmetic prerequisites for polynomial certificates

libmeanfield/interface/solver/enthalpy_admissibility.cppm

@@ -15,6 +15,12 @@ module;
 #include <mfem.hpp>
 #include <mpi.h>
 
+// Outward enclosure depends on ordinary floating-point operations. Optimizers
+// that discard NaNs or reassociate expressions invalidate the certificate.
+#if defined(__FAST_MATH__) || (defined(__FINITE_MATH_ONLY__) && __FINITE_MATH_ONLY__ > 0)
+#error "Polynomial enthalpy certification does not support fast-math or finite-math-only compilation."
+#endif
+
 export module mean_field:solver.enthalpy_admissibility;
 export import :field.mfem;
 
@@ -54,6 +60,11 @@ export namespace mean_field::solver {
 }
 
 namespace mean_field::solver::enthalpy_detail {
+    static_assert(std::numeric_limits<double>::is_iec559 && std::numeric_limits<double>::radix == 2 &&
+                  std::numeric_limits<double>::digits == 53 && std::numeric_limits<double>::max_exponent == 1024 &&
+                  std::numeric_limits<double>::has_denorm == std::denorm_present,
+                  "Polynomial enthalpy certification requires IEEE 754 binary64 with subnormal support.");
+
     // Bounds concern the represented polynomial, not a tolerance-relaxed EOS.
     // Exact zero is retained algebraically so a prescribed zero trace does not
     // become an unresolved negative interval merely through outward rounding.