Connect HHT field convergence to production acceptance and v2 logs

docs/contracts.md

@@ -105,3 +105,27 @@ Procedure는 family별 completed outcome을 반환하며 로그 close와 최종
 Hex8/HHT Python 비교기는 입력·reference·HDF5를 읽고 지정한 JSON report만 쓴다.
 Solver를 기동하거나 원본을 수정하지 않는다. 입력 부재·hash 충돌·schema/identity/finite
 불일치는 실패이며 합성 fixture 통과는 실제 모델 성공을 뜻하지 않는다.
+
+## Shell HHT iteration 로그 독자
+
+Frame0과 직접 v1 writer는 기존 `hht-log-v1` 의미를 유지한다. 양의 reduced-coordinate
+MITC4 HHT 증분은 `hht-log-v2`, `policy_id=abaqus2025-field-on-fesa-v1`을 기록하므로
+한 파일 안의 각 record에서 schema를 읽는다. v1 숫자를 v2 field 값으로 재해석하지 않는다.
+V2의 고정 키 순서·분기·단위·평균·threshold는
+[field 수렴 정식화](abaqus-tolerance/formulation-convergence.md#로그-소비-계약)를 따른다.
+`strict_` 진단은 기존 힘/모멘트 residual과 무차원 q/v/a/A correction이며 종료 기준이 아니다.
+
+UTF-8 LF 한 줄과 tab 구분 key=value를 사용한다. 첫 `=`만 구분자이며 값의 backslash,
+tab, LF, CR은 각각 `\\`, `\t`, `\n`, `\r`로 escape한다. 미평가 numeric/bool은
+literal `not-evaluated`, 평가 bool은 `0`/`1`이다. 독자는 중복·필수키 누락·알 수 없는
+branch/policy/schema·NaN/Inf를 오류로 처리한다. 숫자는 locale-independent binary64
+round-trip 표현이며 step은 raw source 이름이다. 실패 전 평가된 부분값만 보존한다.
+`field_pass=1`은 후속 acceptance 통과를 뜻하지 않는다. `accepted=1`도 최종 HDF5 성공을
+뜻하지 않으며 CLI exit와 완결 결과 identity를 함께 확인한다. 실패 증분은 accepted
+frame/private/flux history에 반영되지 않는다.
+
+현재 acceptance transaction은 기존 accepted frame 전체를 가진 state를 지역 staged copy로
+검증·commit한 뒤 로그 write/flush 성공 시 move로 공개한다. private/flux history도 같은
+성공 경계에서만 교체한다. 이 최소 구현은 증분마다 누적 frame 수에 비례하는 copy 시간과
+추가 메모리를 사용하므로 전체 실행의 복사 비용은 frame 수에 대해 이차로 증가할 수 있다.
+후보의 실제 elapsed 측정에는 이 비용을 포함하며 출력 실패 안전성을 위해 이를 생략하지 않는다.

include/fesa/analysis/newton_iteration_log.h

@@ -5,6 +5,7 @@
 #include <cstdint>
 #include <filesystem>
 #include <fstream>
+#include <optional>
 #include <string>
 
 #include "fesa/analysis/nonlinear_static_control.h"
@@ -52,6 +53,17 @@ struct NewtonIterationLogRecord {
   bool combined_passed;
 };
 
+/// @brief Vendor-neutral field evidence in full global u/total-phi coordinates.
+/// @note Missing quantities serialize as literal not-evaluated. Force uses
+/// force/length units; generalized moment uses moment/rad units.
+struct DynamicFieldLogEvidence {
+  std::optional<double> residual_numerator, residual_scale, spatial_flux;
+  std::optional<double> time_average_flux, correction_numerator, increment_norm;
+  std::optional<double> estimated_correction, residual_threshold, correction_threshold;
+  std::string branch = "not-evaluated";
+  std::optional<bool> residual_pass, correction_pass, field_pass;
+};
+
 /// @brief Carries two-channel HHT endpoint convergence evidence.
 /// @note Array entries are translation and rotation channels, respectively.
 /// Corrections are dimensionless N2 metrics; rate corrections already include
@@ -71,6 +83,14 @@ struct DynamicNewtonIterationLogRecord {
   std::array<double, 2U> algorithmic_correction{};
   bool residual_pass = false;
   bool correction_pass = false;
+  // Absent policy preserves the historical v1 direct-writer/frame-zero contract.
+  std::string policy_id;
+  std::string step_name;
+  std::array<DynamicFieldLogEvidence, 2U> fields;
+  std::optional<bool> field_pass;
+  bool accepted = false;
+  bool strict_residual_evaluated = false;
+  bool strict_correction_evaluated = false;
 };
 
 /// @brief Writes deterministic, line-oriented Newton iteration diagnostics.
@@ -90,7 +110,7 @@ class NewtonIterationLogWriter {
   /// failure with code `log-output-failure`.
   Status Write(const NewtonIterationLogRecord& record);
 
-  /// @brief Writes one complete HHT record using schema `hht-log-v1`.
+  /// @brief Writes HHT v1 evidence, or v2 when the field policy is identified.
   /// @return Success after the complete line is written; invalid numeric
   /// evidence or stream failure permanently fails this writer instance.
   Status Write(const DynamicNewtonIterationLogRecord& record);

src/fesa/analysis/hht_dynamic_assembly.cpp

@@ -191,8 +191,34 @@ Result<double> ReferenceLength(const Domain& domain) {
   return Result<double>::Success(length);
 }
 
+Result<std::array<hht_field_convergence::FieldInput, 2>> MeasureEndpointFields(
+    const DofManager& dofs, const DynamicAcceptedFrameState& trial,
+    const DynamicAcceptedFrameState& accepted, const std::optional<Vector>& previous) {
+  using Fields = std::array<hht_field_convergence::FieldInput, 2>;
+  const auto count = dofs.FullDofCount();
+  if (trial.generalized_coordinates.Size() != count || trial.residual.Size() != count ||
+      accepted.generalized_coordinates.Size() != count || (previous && previous->Size() != count))
+    return Result<Fields>::Failure(Failure("Invalid full endpoint field inventory."));
+  Fields fields;
+  for (auto& field : fields) if (previous) field.correction = 0.0;
+  for (const auto full : dofs.FreeDofs()) {
+    auto& field = fields[full % 6U < 3U ? 0U : 1U];
+    const double residual = std::abs(trial.residual[full]);
+    const double increment = std::abs(trial.generalized_coordinates[full] - accepted.generalized_coordinates[full]);
+    const double correction = previous ? std::abs(trial.generalized_coordinates[full] - (*previous)[full]) : 0.0;
+    if (!std::isfinite(residual) || !std::isfinite(increment) || !std::isfinite(correction))
+      return Result<Fields>::Failure(Failure("Nonfinite full endpoint field arithmetic."));
+    field.active = true;
+    field.residual = (std::max)(field.residual, residual);
+    field.increment = (std::max)(field.increment, increment);
+    if (previous) field.correction = (std::max)(*field.correction, correction);
+  }
+  return Result<Fields>::Success(std::move(fields));
+}
+
 Result<std::array<Vector, 2>> AssembleLoads(const Domain& domain,
-                                            const DofManager& dofs) {
+    const DofManager& dofs,
+    std::array<std::vector<hht_field_convergence::FluxOccurrence>, 2>* field_flux) {
   const auto index = SourceTargetIndex::FromDomain(domain);
   const SourceTargetResolver resolver(index);
   const LoadContext context{domain, dofs, resolver};
@@ -203,6 +229,9 @@ Result<std::array<Vector, 2>> AssembleLoads(const Domain& domain,
     if (!contributions.HasValue())
       return Result<std::array<Vector, 2>>::Failure(contributions.GetStatus());
     for (const auto& entry : contributions.Value()) {
+      if (field_flux != nullptr)
+        (*field_flux)[entry.full_dof_index % 6U < 3U ? 0U : 1U].push_back(
+            {entry.value, 0.0});
       result[0U][entry.full_dof_index] += entry.value;
       result[1U][entry.full_dof_index] += std::abs(entry.value);
       if (!std::isfinite(result[0U][entry.full_dof_index]) ||
@@ -489,6 +518,7 @@ Result<DynamicAssembly> EvaluateAssembly(
   Vector third(count);
   Vector third_scale(count);
   std::array<std::vector<CooContribution>, 6> entries;
+  std::array<std::vector<hht_field_convergence::FluxOccurrence>, 2> field_flux;
   for (auto& values : entries) values.reserve(shells.size() * 24U * 24U);
   double momentum_scale = 0.0;
   double angular_scale = 0.0;
@@ -546,6 +576,8 @@ Result<DynamicAssembly> EvaluateAssembly(
     const Vector mass_action = EntryProducts(mass_values, acceleration_values);
     for (std::size_t row = 0U; row < 24U; ++row) {
       const auto global = shells[e].scatter[row];
+      field_flux[row % 6U < 3U ? 0U : 1U].push_back(
+          {f.internal_force[row], m.force[row]});
       frame.internal_force[global] += f.internal_force[row];
       frame.inertia_force[global] += m.force[row];
       third[global] += f.force_directional_second[row];
@@ -708,7 +740,7 @@ Result<DynamicAssembly> EvaluateAssembly(
        std::move(third), std::move(third_scale), std::move(rotations),
        momentum_scale, angular_scale, std::move(hidden_second),
        std::move(hidden_second_scale), std::move(hidden_gradient),
-       std::move(trial_constraints)});
+       std::move(trial_constraints), std::move(field_flux)});
 }
 
 Status CompleteEquilibrium(const Domain& domain, const DofManager& dofs,

src/fesa/analysis/hht_dynamic_internal.h

@@ -16,6 +16,7 @@
 #include "fesa/math/sparse_matrix.h"
 #include "elements/nonlinear_mitc4_configuration_internal.h"
 #include "math/dense_blas_internal.h"
+#include "analysis/hht_field_convergence.h"
 
 namespace fesa {
 class LinearSolver;
@@ -95,6 +96,7 @@ struct DynamicAssembly {
   // Canonical scalar drilling-constraint derivative, indexed by global node.
   std::optional<SparseMatrix> hidden_gradient;
   std::optional<TrialConstraintData> trial_constraints;
+  std::array<std::vector<hht_field_convergence::FluxOccurrence>, 2> field_flux;
 };
 
 /// @brief Builds checked shell evaluators in stable source order.
@@ -104,9 +106,17 @@ Result<std::vector<RuntimeShell>> BuildRuntimeShells(const Domain& domain,
 /// @brief Returns the maximum initial active-element edge length.
 Result<double> ReferenceLength(const Domain& domain);
 
+/// @brief Measures free full endpoint residuals and actual u/total-phi changes.
+/// @note Previous is the selected trial in this increment, not a tangent lift.
+Result<std::array<hht_field_convergence::FieldInput, 2>> MeasureEndpointFields(
+    const DofManager& dofs, const DynamicAcceptedFrameState& trial,
+    const DynamicAcceptedFrameState& accepted,
+    const std::optional<Vector>& previous);
+
 /// @brief Assembles dead loads and their uncancelled absolute row scales.
 Result<std::array<Vector, 2>> AssembleLoads(const Domain& domain,
-                                            const DofManager& dofs);
+    const DofManager& dofs,
+    std::array<std::vector<hht_field_convergence::FluxOccurrence>, 2>* field_flux = nullptr);
 
 /// @brief Evaluates current kinetic and internal quantities without commit.
 Result<DynamicAssembly> EvaluateAssembly(

src/fesa/analysis/hht_reduced_procedure.cpp

@@ -150,7 +150,7 @@ void ResidualRecord(const DofManager& dofs,
                           frame.free_residual_metrics[1U] <= 1e-10;
 }
 
-void CorrectionRecord(const Vector& coordinate, const Vector& velocity,
+bool CorrectionRecord(const Vector& coordinate, const Vector& velocity,
                       const Vector& acceleration,
                       const Vector& full_algorithmic,
                       const Vector& reduced_algorithmic,
@@ -189,12 +189,14 @@ void CorrectionRecord(const Vector& coordinate, const Vector& velocity,
   if (reduced_algorithmic.Size() != chart.p_columns.size() ||
       reduced_physical.Size() != chart.p_columns.size()) {
     record->correction_pass = false;
-    return;
+    return false;
   }
+  bool private_pass = true;
   for (std::size_t i = 0U; i < chart.p_dofs.size(); ++i)
-    record->correction_pass = record->correction_pass &&
-                              PrivateCorrectionEqual(chart, i, full_algorithmic,
-                                  reduced_algorithmic, reduced_physical, alpha);
+    private_pass = private_pass && PrivateCorrectionEqual(
+        chart, i, full_algorithmic, reduced_algorithmic, reduced_physical, alpha);
+  record->correction_pass = record->correction_pass && private_pass;
+  return private_pass;
 }
 
 bool ExactlyEqual(const Vector& left, const Vector& right) {
@@ -433,7 +435,8 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
   auto length_result = ReferenceLength(domain);
   if (!length_result.HasValue()) return Result<DynamicExecutionResult>::Failure(length_result.GetStatus());
   const double length = length_result.Value();
-  auto loads = AssembleLoads(domain, dofs);
+  std::array<std::vector<hht_field_convergence::FluxOccurrence>, 2> load_flux;
+  auto loads = AssembleLoads(domain, dofs, &load_flux);
   if (!loads.HasValue()) return Result<DynamicExecutionResult>::Failure(loads.GetStatus());
   auto parameters_result = MakeHhtParameters(domain.Dynamic()->alpha);
   if (!parameters_result.HasValue()) return Result<DynamicExecutionResult>::Failure(parameters_result.GetStatus());
@@ -699,9 +702,11 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
   status = log.Write(record); if (status.IsOk()) status = log.Flush();
   if (!status.IsOk()) return Result<DynamicExecutionResult>::Failure(status);
 
+  std::array<hht_field_convergence::History, 2> flux_history{};
   struct ReducedStepCandidate {
     DynamicAcceptedFrameState frame;
     ReducedHistory history;
+    std::array<hht_field_convergence::History, 2> flux_history;
   };
   for (std::uint32_t increment = 1U;
        increment <= domain.Dynamic()->increment_count; ++increment) {
@@ -711,9 +716,14 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
           domain, failure, stage, increment, record.time);
       record.stage = stage;
       record.outcome = "failed";
-      record.failure_code = contextual.Diagnostics().empty()
-                                ? "dynamic-solver-failure"
-                                : contextual.Diagnostics().front().code;
+      record.accepted = false;
+      const auto cause = std::find_if(
+          failure.Diagnostics().begin(), failure.Diagnostics().end(),
+          [](const Diagnostic& diagnostic) {
+            return diagnostic.code != "dynamic-procedure-context";
+          });
+      record.failure_code = cause == failure.Diagnostics().end()
+                                ? "dynamic-solver-failure" : cause->code;
       const Status written = log.Write(record);
       return written.IsOk() ? contextual : written;
     };
@@ -744,6 +754,10 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
           record.increment_index = increment;
           record.time = trial_frame.time;
           record.correction_pass = true;
+          record.policy_id = hht_field_convergence::kPolicyId;
+          record.step_name = domain.Dynamic()->source_step_name_raw;
+          std::optional<Vector> previous_selected_q;
+          std::array<std::optional<double>, 2> previous_residual, older_residual;
           bool translation_private_algorithmic_pass = true;
           bool copy_translation_rates = false;
           Vector retained_velocity{history.p.Size()};
@@ -755,6 +769,9 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
               };
           ReducedShellHhtStep<ReducedStepCandidate> iteration_step(
               [&](std::uint32_t iteration) -> StepResult {
+                record.fields = {};
+                record.field_pass.reset();
+                record.strict_residual_evaluated = false;
                 record.iteration_index = iteration;
                 record.stage = "evaluation";
                 record.outcome = "candidate";
@@ -896,7 +913,53 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
                 if (!operators.HasValue())
                   return fail(operators.GetStatus());
                 ResidualRecord(dofs, candidate, &record);
-                if (record.residual_pass && record.correction_pass) {
+                record.strict_residual_evaluated = true;
+                auto measured_fields = MeasureEndpointFields(dofs, candidate, old, previous_selected_q);
+                if (!measured_fields.HasValue()) return fail(measured_fields.GetStatus());
+                auto field_inputs = std::move(measured_fields.Value());
+                for (std::size_t c = 0; c < 2; ++c) {
+                  field_inputs[c].flux = trial.Value().assembly.field_flux[c];
+                  field_inputs[c].flux.insert(field_inputs[c].flux.end(),
+                                             load_flux[c].begin(), load_flux[c].end());
+                  field_inputs[c].previous_residual = previous_residual[c];
+                  field_inputs[c].older_residual = older_residual[c];
+                }
+                const auto field_evaluation = hht_field_convergence::Evaluate(
+                    field_inputs, flux_history, iteration, length);
+                for (std::size_t c = 0; c < 2; ++c) {
+                  auto& e = record.fields[c];
+                  const auto& in = field_inputs[c];
+                  const auto& out = field_evaluation.fields[c];
+                  if (in.active) {
+                    e.residual_numerator = in.residual;
+                    e.increment_norm = in.increment;
+                    e.correction_numerator = in.correction;
+                  }
+                  e.residual_scale = out.residual_scale;
+                  e.spatial_flux = out.spatial_flux;
+                  e.time_average_flux = out.time_average_flux;
+                  e.estimated_correction = out.estimated_correction;
+                  e.residual_threshold = out.residual_threshold;
+                  e.correction_threshold = out.correction_threshold;
+                  e.residual_pass = out.residual_pass;
+                  e.correction_pass = out.correction_pass;
+                  e.field_pass = out.field_pass;
+                  using Branch = hht_field_convergence::Branch;
+                  switch (out.branch) {
+                    case Branch::kNotEvaluated: e.branch = "not-evaluated"; break;
+                    case Branch::kLinear: e.branch = "linear"; break;
+                    case Branch::kZeroFlux: e.branch = "zero-flux"; break;
+                    case Branch::kNonquadratic: e.branch = "nonquadratic"; break;
+                    case Branch::kNormal: e.branch = "normal"; break;
+                  }
+                }
+                if (!field_evaluation.status.IsOk()) return fail(field_evaluation.status);
+                record.field_pass = field_evaluation.field_pass;
+                previous_selected_q = candidate.generalized_coordinates;
+                older_residual = previous_residual;
+                for (std::size_t c = 0; c < 2; ++c)
+                  previous_residual[c] = field_inputs[c].residual;
+                if (field_evaluation.field_pass) {
                   status = CompleteConstraintEvidence(
                       domain, dofs, trial.Value().assembly, length, null_nodes,
                       positive_solver, tangent_solver, &candidate);
@@ -932,7 +995,7 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
                   return StepResult::Success(ReducedStepCandidate{
                       std::move(candidate),
                       {trial_p, trial_v, trial_a, trial_algorithmic,
-                       trial.Value().root.z}});
+                       trial.Value().root.z}, field_evaluation.pending});
                 }
                 if (!CanApplyOuterCorrection(iteration)) {
                   double full_hidden = 0.0;
@@ -1059,11 +1122,15 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
                       correction.Value().p[i] / (parameters.beta * h * h);
                   reduced_physical[i] = acceleration_rate * correction.Value().p[i];
                 }
-                CorrectionRecord(correction.Value().coordinate,
+                const bool private_correction_pass = CorrectionRecord(correction.Value().coordinate,
                                  correction.Value().velocity,
                                  correction.Value().acceleration, full_algorithmic,
                                  reduced_algorithmic, reduced_physical, chart.Value(),
                                  dofs, length, h, parameters.alpha, &record);
+                record.strict_correction_evaluated = true;
+                if (!private_correction_pass)
+                  return fail(Failure(domain, "reduced-dynamic-update-inconsistency",
+                      "The full/private correction acceleration arithmetic is inconsistent."));
                 translation_private_algorithmic_pass = true;
                 for (std::size_t i = 0U; i < chart.Value().p_dofs.size(); ++i)
                   if (PhysicalCoordinateChannel(chart.Value(), i) == 0U)
@@ -1115,16 +1182,21 @@ Result<DynamicExecutionResult> ExecuteReducedHht(
               iteration_step.TakeCandidate());
         },
         [&](ReducedStepCandidate&& accepted_candidate) -> Status {
-          status = state.CommitAcceptedFrame(accepted_candidate.frame);
-          if (!status.IsOk())
-            return report_failure(status, "accepted");
-          history = std::move(accepted_candidate.history);
+          // Stage the complete accepted history. Output failure discards all
+          // three snapshots; publication below consists only of noexcept moves.
+          auto staged_state = state;
+          status = staged_state.CommitAcceptedFrame(accepted_candidate.frame);
+          if (!status.IsOk()) return report_failure(status, "accepted");
           record.stage = "accepted";
           record.outcome = "accepted";
+          record.accepted = true;
           status = log.Write(record);
-          if (status.IsOk())
-            status = log.Flush();
-          return status;
+          if (status.IsOk()) status = log.Flush();
+          if (!status.IsOk()) return status;
+          state = std::move(staged_state);
+          history = std::move(accepted_candidate.history);
+          flux_history = accepted_candidate.flux_history;
+          return Status::Ok();
         });
     if (!status.IsOk()) return Result<DynamicExecutionResult>::Failure(status);
   }

src/fesa/analysis/newton_iteration_log.cpp

@@ -261,10 +261,100 @@ Result<std::string> SerializeRecord(const NewtonIterationLogRecord& record,
   return Result<std::string>::Success(std::move(line));
 }
 
+// Candidate policy has separate names and units; v1 evidence is never redefined.
+Result<std::string> SerializeFieldRecord(
+    const DynamicNewtonIterationLogRecord& record,
+    const std::filesystem::path& path) {
+  if (record.policy_id != "abaqus2025-field-on-fesa-v1" ||
+      record.time < 0.0 || record.stage.empty() || record.outcome.empty())
+    return Result<std::string>::Failure(
+        LogOutputFailure(path, "Invalid HHT field-policy log identity."));
+  std::vector<std::string> fields;
+  const auto number = [&](const std::string& key,
+                          const std::optional<double>& value) -> Status {
+    if (!value.has_value()) {
+      AppendField(&fields, key, "not-evaluated");
+      return Status::Ok();
+    }
+    auto formatted = FormatFiniteNumber(*value, path);
+    if (!formatted.HasValue()) return formatted.GetStatus();
+    if (*value < 0.0)
+      return LogOutputFailure(path, "Negative HHT field norm or scale.");
+    AppendField(&fields, key, formatted.Value());
+    return Status::Ok();
+  };
+  const auto boolean = [&](const std::string& key, const std::optional<bool>& value) {
+    AppendField(&fields, key, value.has_value() ? (*value ? "1" : "0") : "not-evaluated");
+  };
+  AppendField(&fields, "record", "dynamic-newton-iteration");
+  AppendField(&fields, "schema", "hht-log-v2");
+  AppendField(&fields, "policy_id", record.policy_id);
+  AppendField(&fields, "step", EscapeText(record.step_name));
+  AppendField(&fields, "increment", std::to_string(record.increment_index));
+  auto status = number("time", record.time);
+  if (!status.IsOk()) return Result<std::string>::Failure(status);
+  AppendField(&fields, "iteration", std::to_string(record.iteration_index));
+  AppendField(&fields, "stage", EscapeText(record.stage));
+  AppendField(&fields, "outcome", EscapeText(record.outcome));
+  AppendField(&fields, "failure_code", EscapeText(record.failure_code));
+  boolean("field_pass", record.field_pass);
+  boolean("accepted", record.accepted);
+  for (std::size_t c = 0; c < 2; ++c) {
+    const auto& e = record.fields[c];
+    const std::string prefix = c == 0 ? "force_" : "moment_";
+    const std::array<std::pair<const char*, std::optional<double>>, 9> numbers{{
+        {"residual_numerator", e.residual_numerator}, {"residual_scale", e.residual_scale},
+        {"spatial_flux", e.spatial_flux}, {"time_average_flux", e.time_average_flux},
+        {"correction_numerator", e.correction_numerator}, {"increment_norm", e.increment_norm},
+        {"estimated_correction", e.estimated_correction}, {"residual_threshold", e.residual_threshold},
+        {"correction_threshold", e.correction_threshold}}};
+    for (const auto& entry : numbers) {
+      status = number(prefix + entry.first, entry.second);
+      if (!status.IsOk()) return Result<std::string>::Failure(status);
+    }
+    AppendField(&fields, prefix + "residual_unit", c == 0 ? "force" : "moment");
+    AppendField(&fields, prefix + "correction_unit", c == 0 ? "length" : "rad");
+    if (e.branch != "normal" && e.branch != "zero-flux" && e.branch != "linear" &&
+        e.branch != "nonquadratic" && e.branch != "not-evaluated")
+      return Result<std::string>::Failure(LogOutputFailure(path, "Invalid HHT field branch."));
+    AppendField(&fields, prefix + "branch", e.branch);
+    boolean(prefix + "residual_pass", e.residual_pass);
+    boolean(prefix + "correction_pass", e.correction_pass);
+    boolean(prefix + "field_pass", e.field_pass);
+  }
+  for (std::size_t c = 0; c < 2; ++c) {
+    const std::string suffix = c == 0 ? "u" : "phi";
+    const auto strict = [&](double value, bool evaluated) {
+      return evaluated ? std::optional<double>{value} : std::nullopt;
+    };
+    const std::array<std::pair<std::string, std::optional<double>>, 6> numbers{{
+        {"residual_" + suffix + "_numerator", strict(record.residual_numerator[c], record.strict_residual_evaluated)},
+        {"residual_" + suffix + "_scale", strict(record.residual_scale[c], record.strict_residual_evaluated)},
+        {"coordinate_correction_" + suffix, strict(record.coordinate_correction[c], record.strict_correction_evaluated)},
+        {"velocity_correction_" + suffix, strict(record.velocity_correction[c], record.strict_correction_evaluated)},
+        {"acceleration_correction_" + suffix, strict(record.acceleration_correction[c], record.strict_correction_evaluated)},
+        {"algorithmic_correction_" + suffix, strict(record.algorithmic_correction[c], record.strict_correction_evaluated)}}};
+    for (const auto& entry : numbers) {
+      status = number("strict_" + entry.first, entry.second);
+      if (!status.IsOk()) return Result<std::string>::Failure(status);
+    }
+  }
+  boolean("strict_residual_pass", record.strict_residual_evaluated ? std::optional<bool>{record.residual_pass} : std::nullopt);
+  boolean("strict_correction_pass", record.strict_correction_evaluated ? std::optional<bool>{record.correction_pass} : std::nullopt);
+  std::string line;
+  for (const auto& field : fields) {
+    if (!line.empty()) line += '\t';
+    line += field;
+  }
+  line += '\n';
+  return Result<std::string>::Success(std::move(line));
+}
+
 /// @brief Serializes dynamic evidence without static load-factor semantics.
 Result<std::string> SerializeRecord(
     const DynamicNewtonIterationLogRecord& record,
     const std::filesystem::path& log_path) {
+  if (!record.policy_id.empty()) return SerializeFieldRecord(record, log_path);
   const auto time = FormatFiniteNumber(record.time, log_path);
   if (!time.HasValue()) return Result<std::string>::Failure(time.GetStatus());
   if (record.time < 0.0 || record.stage.empty() || record.outcome.empty()) {

tests/unit/analysis/hht_dynamic_algebra_test.cpp

@@ -669,4 +669,39 @@ TEST(HhtDynamicAlgebra, RejectsAdmissibleNullRankChangeBeforeAcceptingFrame) {
   EXPECT_EQ(frame.hidden_constraint[0], 23.0);
 }
 
+TEST(HhtEndpointFields, MeasuresActualFullChartAcrossNonlinearRootAndPartialBoundary) {
+  const auto fixture = MakeFixture(1U, true);
+  auto trial = EmptyTrial(fixture), old = EmptyTrial(fixture);
+  trial.residual = fesa::Vector{24U};
+  fesa::Vector previous{24U};
+  // Independent nonlinear graph q_phiZ=p^2: p .1 -> .2. The
+  // previous tangent lift is .02, while the actual endpoint change is .03.
+  previous[0] = .1; previous[5] = .01;
+  trial.generalized_coordinates[0] = .2;
+  trial.generalized_coordinates[5] = .04;
+  trial.residual[0] = 3; trial.residual[5] = -5;
+  // Large constrained values and spatial support moments are not free
+  // generalized endpoint evidence and cannot change either scalar maximum.
+  trial.generalized_coordinates[3] = 1000;
+  trial.residual[3] = 2000;
+  trial.reaction = fesa::Vector{24U}; trial.reaction[5] = 3000;
+  const auto result = fesa::hht_internal::MeasureEndpointFields(fixture.dofs, trial, old, previous);
+  ASSERT_TRUE(result.HasValue());
+  EXPECT_TRUE(result.Value()[0].active); EXPECT_TRUE(result.Value()[1].active);
+  EXPECT_DOUBLE_EQ(result.Value()[0].residual, 3);
+  EXPECT_DOUBLE_EQ(result.Value()[1].residual, 5);
+  EXPECT_DOUBLE_EQ(result.Value()[0].increment, .2);
+  EXPECT_DOUBLE_EQ(result.Value()[1].increment, .04);
+  EXPECT_DOUBLE_EQ(*result.Value()[0].correction, .2 - .1);
+  EXPECT_DOUBLE_EQ(*result.Value()[1].correction, .04 - .01);
+  EXPECT_NE(*result.Value()[1].correction, 2 * .1 * (.2 - .1));
+  const auto initial = fesa::hht_internal::MeasureEndpointFields(fixture.dofs, trial, old, std::nullopt);
+  ASSERT_TRUE(initial.HasValue());
+  EXPECT_FALSE(initial.Value()[0].correction.has_value());
+  EXPECT_FALSE(initial.Value()[1].correction.has_value());
+  previous[0] = -std::numeric_limits<double>::max();
+  trial.generalized_coordinates[0] = std::numeric_limits<double>::max();
+  EXPECT_FALSE(fesa::hht_internal::MeasureEndpointFields(fixture.dofs, trial, old, previous).HasValue());
+}
+
 }  // namespace

tests/unit/analysis/hht_dynamic_procedure_test.cpp

@@ -8,9 +8,16 @@
 #include <fstream>
 #include <iterator>
 #include <optional>
+#include <sstream>
+#include <map>
 #include <string>
 
 #include "fesa/analysis/newton_iteration_log.h"
+#include "fesa/analysis/analysis_model.h"
+#include "analysis/hht_dynamic_internal.h"
+#include "analysis/hht_reduced_integrator.h"
+#include "analysis/hht_reduced_procedure.h"
+#include "analysis/equilibrium_algorithm.h"
 #include "fesa/assembly/parallel_for.h"
 #include "fesa/solvers/linear/mkl_pardiso_solver.h"
 #include "fesa/solvers/linear/mkl_pardiso_tangent_solver.h"
@@ -569,3 +576,355 @@ TEST(HhtDynamicProcedure,
 }
 
 }  // namespace
+
+namespace {
+std::map<std::string, std::string> LogFields(const std::string& line) {
+  std::map<std::string, std::string> fields;
+  std::istringstream input(line);
+  std::string token;
+  while (std::getline(input, token, '\t')) {
+    const auto equal = token.find('=');
+    if (equal != std::string::npos) fields.emplace(token.substr(0, equal), token.substr(equal + 1));
+  }
+  return fields;
+}
+}
+
+namespace {
+fesa::ModelDefinition SymmetricExtension() {
+  auto definition = MakeDefinition(false);
+  definition.dynamic_step->initial_increment = 0.1;
+  definition.dynamic_step->time_period = 0.1;
+  definition.dynamic_step->increment_count = 1U;
+  definition.node_sets.push_back({"Left", std::nullopt, {0U, 3U}, {"dynamic-state.inp", 30U}});
+  definition.node_sets.push_back({"Right", std::nullopt, {1U, 2U}, {"dynamic-state.inp", 31U}});
+  definition.dynamic_step->boundaries = {
+      {"All", 2, 6, 0.0, {"dynamic-state.inp", 32U}}};
+  definition.dynamic_step->loads = {
+      {"Left", 1, -1.0, {"dynamic-state.inp", 33U}},
+      {"Right", 1, 1.0, {"dynamic-state.inp", 34U}}};
+  return definition;
+}
+}
+
+TEST(HhtDynamicProcedure, FieldPolicyActuallyTerminatesSymmetricExtensionBeforeStrict) {
+  auto definition = SymmetricExtension();
+  fesa::SerialParallelFor parallel;
+  auto run = RunRigidTranslation(definition, parallel, "field-policy-extension");
+  ASSERT_TRUE(run.HasValue()) << (run.HasValue() ? "" : FailureText(run.GetStatus()));
+  const auto& frame = run.Value().execution.state.CommittedState();
+  ASSERT_GT(frame.iteration_count, 0U);
+  ASSERT_LE(frame.iteration_count, 100U);
+  const auto& text = run.Value().log;
+  const auto accepted = text.rfind("record=dynamic-newton-iteration");
+  ASSERT_NE(accepted, std::string::npos);
+  const auto line = text.substr(accepted);
+  EXPECT_NE(line.find("\tschema=hht-log-v2\t"), std::string::npos);
+  EXPECT_NE(line.find("\tpolicy_id=abaqus2025-field-on-fesa-v1\t"), std::string::npos);
+  EXPECT_NE(line.find("\tstep=Transient Load\t"), std::string::npos);
+  EXPECT_NE(line.find("\tfield_pass=1\taccepted=1\t"), std::string::npos);
+  EXPECT_NE(line.find("\tstrict_correction_pass=0"), std::string::npos);
+  for (const auto value : frame.global_equilibrium) EXPECT_LE(std::abs(value), 1e-8);
+  auto fields = LogFields(line.substr(0, line.find('\n')));
+  double rho = 0, increment = 0, flux = 4.0;
+  for (std::size_t node = 0; node < 4; ++node) {
+    rho = (std::max)(rho, std::abs(frame.residual[6 * node]));
+    increment = (std::max)(increment, std::abs(frame.generalized_coordinates[6 * node]));
+    for (std::size_t c = 0; c < 3; ++c)
+      flux += std::abs(frame.internal_force[6 * node + c] + frame.inertia_force[6 * node + c]);
+  }
+  EXPECT_DOUBLE_EQ(std::stod(fields.at("force_residual_numerator")), rho);
+  EXPECT_DOUBLE_EQ(std::stod(fields.at("force_increment_norm")), increment);
+  EXPECT_DOUBLE_EQ(std::stod(fields.at("force_spatial_flux")), flux / 24.0);
+  EXPECT_DOUBLE_EQ(std::stod(fields.at("force_time_average_flux")), flux / 24.0);
+  EXPECT_LE(rho, .005 * std::stod(fields.at("force_residual_scale")));
+  EXPECT_DOUBLE_EQ(std::stod(fields.at("force_residual_threshold")), .005);
+  EXPECT_DOUBLE_EQ(std::stod(fields.at("force_correction_threshold")), .01);
+  EXPECT_EQ(fields.at("force_residual_pass"), "1");
+  EXPECT_EQ(fields.at("force_correction_pass"), "1");
+  const double c = std::stod(fields.at("force_correction_numerator"));
+  const auto& estimated = fields.at("force_estimated_correction");
+  EXPECT_TRUE(c <= .01 * increment ||
+              (estimated != "not-evaluated" && std::stod(estimated) <= .01 * increment));
+  EXPECT_EQ(fields.at("force_branch"), "normal");
+  EXPECT_EQ(fields.at("moment_branch"), "not-evaluated");
+  // Symmetric monotone extension has q=(-D,+D,+D,-D). This independent
+  // endpoint oracle includes the selected iteration-zero start, not the lift.
+  std::istringstream records(text);
+  std::string row;
+  double previous_D = 0;
+  bool first = true;
+  while (std::getline(records, row)) {
+    const auto values = LogFields(row);
+    if (values.at("schema") != "hht-log-v2") continue;
+    const double D = std::stod(values.at("force_increment_norm"));
+    if (first) {
+      EXPECT_EQ(values.at("force_correction_numerator"), "not-evaluated");
+      EXPECT_EQ(values.at("force_estimated_correction"), "not-evaluated");
+      EXPECT_EQ(values.at("field_pass"), "0");
+    } else {
+      EXPECT_NEAR(std::stod(values.at("force_correction_numerator")),
+                  std::abs(D - previous_D), 1e-16);
+    }
+    previous_D = D;
+    first = false;
+  }
+}
+
+TEST(HhtDynamicProcedure, FieldPassDoesNotBypassPhysicalAcceptanceAndLogsActualCause) {
+  auto definition = MakeDefinition(false);
+  definition.materials[0].youngs_modulus = 1e9;
+  definition.dynamic_step->increment_count = 1;
+  definition.dynamic_step->time_period = definition.dynamic_step->initial_increment;
+  definition.node_sets[0].node_indices = {0U, 3U};
+  definition.node_sets[1].node_indices = {2U};
+  definition.dynamic_step->boundaries = {{"All", 1, 6, 0, {"dynamic-state.inp", 11U}}};
+  definition.dynamic_step->loads = {{"Loaded", 3, -40000, {"dynamic-state.inp", 12U}}};
+  auto domain = fesa::Domain::Create(definition);
+  ASSERT_TRUE(domain.HasValue());
+  fesa::SerialParallelFor parallel;
+  fesa::MklPardisoSolver mass;
+  fesa::MklPardisoTangentSolver tangent;
+  fesa::NewtonIterationLogWriter log;
+  const auto path = std::filesystem::temp_directory_path() / "fesa-field-post-gate.log";
+  ASSERT_TRUE(log.Open(path).IsOk());
+  auto result = fesa::HhtDynamicProcedureExecutor(parallel, mass, tangent).Execute(domain.Value(), log);
+  ASSERT_TRUE(log.Close().IsOk());
+  std::ifstream input(path, std::ios::binary);
+  const std::string text{std::istreambuf_iterator<char>{input}, {}};
+  input.close();
+  std::filesystem::remove(path);
+  ASSERT_FALSE(result.HasValue());
+  const auto row = text.substr(text.rfind("record="));
+  const auto fields = LogFields(row.substr(0, row.find('\n')));
+  EXPECT_EQ(fields.at("field_pass"), "1");
+  EXPECT_EQ(fields.at("accepted"), "0");
+  EXPECT_EQ(fields.at("outcome"), "failed");
+  const auto cause = std::find_if(result.GetStatus().Diagnostics().begin(),
+      result.GetStatus().Diagnostics().end(), [](const auto& d) {
+        return d.code != "dynamic-procedure-context";
+      });
+  ASSERT_NE(cause, result.GetStatus().Diagnostics().end());
+  EXPECT_EQ(fields.at("failure_code"), cause->code) << FailureText(result.GetStatus());
+  EXPECT_EQ(text.find("\taccepted=1"), std::string::npos);
+}
+
+TEST(HhtDynamicProcedure, AcceptedFluxHistoryCountsEachIncrementExactlyOnce) {
+  auto definition = SymmetricExtension();
+  definition.dynamic_step->time_period = .2;
+  definition.dynamic_step->increment_count = 2;
+  fesa::SerialParallelFor parallel;
+  auto run = RunRigidTranslation(definition, parallel, "field-history");
+  ASSERT_TRUE(run.HasValue()) << (run.HasValue() ? "" : FailureText(run.GetStatus()));
+  const auto& frames = run.Value().execution.state.AcceptedFrames();
+  ASSERT_EQ(frames.size(), 3U);
+  double sum = 0, maximum_sum = 0;
+  std::size_t n = 0;
+  std::istringstream input(run.Value().log);
+  std::string row;
+  while (std::getline(input, row)) {
+    const auto fields = LogFields(row);
+    if (fields.at("schema") != "hht-log-v2" || fields.at("accepted") != "1") continue;
+    ++n;
+    const auto& frame = frames[n];
+    std::vector<double> flux;
+    for (std::size_t node = 0; node < 4; ++node)
+      for (std::size_t c = 0; c < 3; ++c)
+        flux.push_back(std::abs(frame.internal_force[6 * node + c] + frame.inertia_force[6 * node + c]));
+    for (int node = 0; node < 4; ++node) {
+      flux.push_back(1); flux.push_back(0); flux.push_back(0);
+    }
+    const double m = *std::max_element(flux.begin(), flux.end());
+    const double H = n == 1 ? 0 : maximum_sum / static_cast<double>(n - 1);
+    double selected_sum = 0;
+    std::size_t count = 0;
+    for (double x : flux)
+      if (m < .1 * H || x >= 1e-5 * H) { selected_sum += x; ++count; }
+    ASSERT_GT(count, 0U);
+    const double spatial = selected_sum / static_cast<double>(count);
+    sum += spatial; maximum_sum += m;
+    EXPECT_DOUBLE_EQ(std::stod(fields.at("force_spatial_flux")), spatial);
+    EXPECT_DOUBLE_EQ(std::stod(fields.at("force_time_average_flux")), sum / static_cast<double>(n));
+    EXPECT_EQ(std::stoul(fields.at("iteration")), frame.iteration_count);
+  }
+  EXPECT_EQ(n, 2U);
+}
+
+TEST(HhtDynamicProcedure, LoadFluxPreservesSourceCancellationAndExplicitZeroEntries) {
+  auto definition = MakeDefinition(true);
+  definition.dynamic_step->loads = {
+      {"Loaded", 1, 3, {"dynamic-state.inp", 30U}},
+      {"Loaded", 1, -3, {"dynamic-state.inp", 31U}},
+      {"Loaded", 2, 0, {"dynamic-state.inp", 32U}}};
+  auto domain = fesa::Domain::Create(definition);
+  ASSERT_TRUE(domain.HasValue());
+  auto model = fesa::AnalysisModel::Create(domain.Value());
+  ASSERT_TRUE(model.HasValue());
+  auto dofs = fesa::DofManager::Create(model.Value());
+  ASSERT_TRUE(dofs.HasValue());
+  std::array<std::vector<fesa::hht_field_convergence::FluxOccurrence>, 2> flux;
+  const auto loads = fesa::hht_internal::AssembleLoads(domain.Value(), dofs.Value(), &flux);
+  ASSERT_TRUE(loads.HasValue());
+  EXPECT_DOUBLE_EQ(loads.Value()[0][0], 0);
+  EXPECT_DOUBLE_EQ(loads.Value()[1][0], 6);
+  ASSERT_EQ(flux[0].size(), 9U);
+  ASSERT_EQ(flux[1].size(), 9U);
+  const std::array<double, 9> expected{3, 0, 0, -3, 0, 0, 0, 0, 0};
+  for (std::size_t i = 0; i < expected.size(); ++i) {
+    EXPECT_DOUBLE_EQ(flux[0][i].internal, expected[i]);
+    EXPECT_DOUBLE_EQ(flux[0][i].inertia, 0);
+    EXPECT_DOUBLE_EQ(flux[1][i].internal, 0);
+  }
+}
+
+namespace {
+// All-fixed fixture has no private coordinates. This adapter exercises the
+// real production acceptance/output transaction without a test solver path.
+class EmptyCoordinateIntegrator final : public fesa::hht_reduced_internal::ShellHhtIntegrator {
+ public:
+  fesa::hht_reduced_internal::ReducedShellPredictor Predict(
+      const fesa::hht_reduced_internal::ReducedHistory& history, double,
+      const fesa::HhtParameters&) const override {
+    EXPECT_EQ(history.p.Size(), 0U);
+    return {};
+  }
+  void EvaluateRates(const fesa::hht_reduced_internal::ReducedShellRateRequest&,
+                     fesa::Vector& v, fesa::Vector& a) const override {
+    EXPECT_EQ(v.Size(), 0U); EXPECT_EQ(a.Size(), 0U);
+  }
+  fesa::Result<fesa::hht_reduced_internal::ReconstructedRates> ReconstructPhysicalRates(
+      const fesa::hht_reduced_internal::FixedChart& chart,
+      const fesa::hht_reduced_internal::EmbeddingRoot& root,
+      const fesa::Vector& v, const fesa::Vector& a,
+      fesa::TangentSolver& solver) const override {
+    return fesa::hht_reduced_internal::ReconstructPhysicalRates(chart, root, v, a, solver);
+  }
+};
+class CloseAtCandidate final : public fesa::EquilibriumAlgorithm {
+ public:
+  explicit CloseAtCandidate(fesa::NewtonIterationLogWriter& log) : log_(log) {}
+  fesa::Status SolveCurrentStep(std::uint32_t first, std::uint32_t last,
+                                const Evaluation& evaluate) override {
+    EXPECT_EQ(first, 0U); EXPECT_EQ(last, 100U);
+    auto value = evaluate(first);
+    if (!value.HasValue()) return value.GetStatus();
+    EXPECT_TRUE(value.Value());
+    return log_.Close();
+  }
+ private:
+  fesa::NewtonIterationLogWriter& log_;
+};
+}
+
+TEST(HhtDynamicProcedure, FailedAcceptanceOutputPublishesNoCandidateAndFreshRetryIsUnchanged) {
+  auto domain = fesa::Domain::Create(MakeDefinition());
+  ASSERT_TRUE(domain.HasValue());
+  fesa::SerialParallelFor parallel;
+  fesa::MklPardisoSolver mass;
+  fesa::MklPardisoTangentSolver tangent;
+  fesa::NewtonIterationLogWriter log;
+  const auto path = std::filesystem::temp_directory_path() / "fesa-field-output-fail.log";
+  ASSERT_TRUE(log.Open(path).IsOk());
+  EmptyCoordinateIntegrator integrator;
+  CloseAtCandidate algorithm(log);
+  const auto result = fesa::ExecuteReducedHht(domain.Value(), log, parallel, mass, tangent, integrator, algorithm);
+  ASSERT_FALSE(result.HasValue());
+  EXPECT_EQ(result.GetStatus().Category(), fesa::FailureCategory::kOutput);
+  std::ifstream input(path, std::ios::binary);
+  const std::string text{std::istreambuf_iterator<char>{input}, {}};
+  input.close(); std::filesystem::remove(path);
+  EXPECT_EQ(text.find("accepted=1"), std::string::npos);
+  auto first = RunRigidTranslation(MakeDefinition(), parallel, "field-retry");
+  auto second = RunRigidTranslation(MakeDefinition(), parallel, "field-retry-repeat");
+  ASSERT_TRUE(first.HasValue()); ASSERT_TRUE(second.HasValue());
+  ExpectSameDynamicHistory(first.Value(), second.Value());
+}
+
+namespace {
+class FailNextSelectedTrial final : public fesa::TangentSolver {
+ public:
+  fesa::Status FactorizeFresh(const fesa::SparseMatrix& matrix) override {
+    if (outer_solved_) return fesa::Status::Failure(fesa::FailureCategory::kSolver,
+        {{fesa::Severity::kError, "injected-next-trial", {}, "DYNAMIC", {}, "Fail before the next selected field evaluation."}});
+    large_ = matrix.Rows() > 4;
+    return solver_.FactorizeFresh(matrix);
+  }
+  fesa::Status SolveCorrection(const fesa::Vector& rhs, fesa::Vector& solution) const override {
+    auto status = solver_.SolveCorrection(rhs, solution);
+    if (status.IsOk() && large_) outer_solved_ = true;
+    return status;
+  }
+ private:
+  fesa::MklPardisoTangentSolver solver_;
+  bool large_ = false;
+  mutable bool outer_solved_ = false;
+};
+}
+
+TEST(HhtDynamicProcedure, FailureBeforeNextEvaluationDoesNotReusePreviousFieldEvidence) {
+  auto domain = fesa::Domain::Create(MakeFiniteRotationDefinition());
+  ASSERT_TRUE(domain.HasValue());
+  fesa::SerialParallelFor parallel;
+  fesa::MklPardisoSolver mass;
+  FailNextSelectedTrial tangent;
+  fesa::NewtonIterationLogWriter log;
+  const auto path = std::filesystem::temp_directory_path() / "fesa-field-next-fail.log";
+  ASSERT_TRUE(log.Open(path).IsOk());
+  const auto result = fesa::HhtDynamicProcedureExecutor(parallel, mass, tangent).Execute(domain.Value(), log);
+  ASSERT_TRUE(log.Close().IsOk());
+  std::ifstream input(path, std::ios::binary);
+  const std::string text{std::istreambuf_iterator<char>{input}, {}};
+  input.close(); std::filesystem::remove(path);
+  ASSERT_FALSE(result.HasValue());
+  const auto row = text.substr(text.rfind("record="));
+  const auto fields = LogFields(row.substr(0, row.find('\n')));
+  EXPECT_EQ(fields.at("failure_code"), "injected-next-trial") << FailureText(result.GetStatus());
+  EXPECT_EQ(fields.at("iteration"), "1");
+  EXPECT_EQ(fields.at("force_residual_numerator"), "not-evaluated");
+  EXPECT_EQ(fields.at("moment_residual_scale"), "not-evaluated");
+  EXPECT_EQ(fields.at("field_pass"), "not-evaluated");
+  EXPECT_EQ(fields.at("accepted"), "0");
+}
+
+namespace {
+class EvaluateEndpoint100 final : public fesa::EquilibriumAlgorithm {
+ public:
+  fesa::Status SolveCurrentStep(std::uint32_t first, std::uint32_t last,
+                                const Evaluation& evaluate) override {
+    EXPECT_EQ(first, 0U); EXPECT_EQ(last, 100U);
+    auto value = evaluate(last);
+    if (!value.HasValue()) return value.GetStatus();
+    EXPECT_TRUE(value.Value());
+    return fesa::Status::Ok();
+  }
+};
+}
+
+TEST(HhtDynamicProcedure, FieldAcceptanceEvaluatesProductionEndpoint100BeforeCorrectionBudget) {
+  auto domain = fesa::Domain::Create(MakeDefinition());
+  ASSERT_TRUE(domain.HasValue());
+  fesa::SerialParallelFor parallel;
+  fesa::MklPardisoSolver mass;
+  fesa::MklPardisoTangentSolver tangent;
+  fesa::NewtonIterationLogWriter log;
+  const auto path = std::filesystem::temp_directory_path() / "fesa-field-endpoint100.log";
+  ASSERT_TRUE(log.Open(path).IsOk());
+  EmptyCoordinateIntegrator integrator;
+  EvaluateEndpoint100 algorithm;
+  // Tests the real endpoint callback at the inclusive boundary. No physical
+  // trajectory is forced through 100 corrections; all fixed coordinates stay zero.
+  const auto result = fesa::ExecuteReducedHht(domain.Value(), log, parallel, mass, tangent, integrator, algorithm);
+  ASSERT_TRUE(log.Close().IsOk());
+  std::ifstream input(path, std::ios::binary);
+  const std::string text{std::istreambuf_iterator<char>{input}, {}};
+  input.close(); std::filesystem::remove(path);
+  ASSERT_TRUE(result.HasValue()) << (result.HasValue() ? "" : FailureText(result.GetStatus()));
+  ASSERT_EQ(result.Value().state.AcceptedFrames().size(), 3U);
+  EXPECT_EQ(result.Value().state.AcceptedFrames()[1].iteration_count, 100U);
+  EXPECT_EQ(result.Value().state.AcceptedFrames()[2].iteration_count, 100U);
+  const auto row = text.substr(text.rfind("record="));
+  const auto fields = LogFields(row.substr(0, row.find('\n')));
+  EXPECT_EQ(fields.at("iteration"), "100");
+  EXPECT_EQ(fields.at("field_pass"), "1");
+  EXPECT_EQ(fields.at("accepted"), "1");
+}

tests/unit/analysis/newton_iteration_log_test.cpp

@@ -8,6 +8,7 @@
 #include <fstream>
 #include <functional>
 #include <limits>
+#include <map>
 #include <iterator>
 #include <stdexcept>
 #include <string>
@@ -562,4 +563,149 @@ TEST(DynamicNewtonIterationLog,
   ExpectLogOutputFailure(unopened.Write(CompleteDynamicRecord()));
 }
 
+TEST(DynamicFieldIterationLog, KeepsOrderedUnitsMissingEvidenceAndEscapedSourceName) {
+  TempDirectory directory{"field-v2"};
+  const auto path = directory.Path() / "log.txt";
+  auto record = CompleteDynamicRecord();
+  record.policy_id = "abaqus2025-field-on-fesa-v1";
+  record.step_name = "\xED\x95\x9C\xEA\xB8\x80=Step\\tail\tline\nend\r";
+  record.stage = "evaluation";
+  record.outcome = "candidate";
+  record.fields[0].residual_numerator = 1.2345678901234567;
+  record.fields[0].increment_norm = 0;
+  fesa::NewtonIterationLogWriter writer;
+  ASSERT_TRUE(writer.Open(path).IsOk());
+  ASSERT_TRUE(writer.Write(record).IsOk());
+  ASSERT_TRUE(writer.Close().IsOk());
+  const auto text = ReadLogBytes(path);
+  EXPECT_EQ(std::count(text.begin(), text.end(), '\n'), 1);
+  EXPECT_EQ(text.find('\r'), std::string::npos);
+  const auto fields = SplitTabs(text.substr(0, text.size() - 1));
+  const std::vector<std::string> base{"record", "schema", "policy_id", "step", "increment", "time", "iteration", "stage", "outcome", "failure_code", "field_pass", "accepted"};
+  for (std::size_t i = 0; i < base.size(); ++i)
+    EXPECT_EQ(fields[i].substr(0, fields[i].find('=')), base[i]);
+  const std::vector<std::string> suffixes{
+      "residual_numerator", "residual_scale", "spatial_flux", "time_average_flux",
+      "correction_numerator", "increment_norm", "estimated_correction",
+      "residual_threshold", "correction_threshold", "residual_unit", "correction_unit",
+      "branch", "residual_pass", "correction_pass", "field_pass"};
+  for (std::size_t c = 0; c < 2; ++c)
+    for (std::size_t i = 0; i < suffixes.size(); ++i)
+      EXPECT_EQ(fields[base.size() + c * suffixes.size() + i].substr(
+          0, fields[base.size() + c * suffixes.size() + i].find('=')),
+          (c == 0 ? "force_" : "moment_") + suffixes[i]);
+  EXPECT_EQ(FieldValue(fields, "step"), "step=\xED\x95\x9C\xEA\xB8\x80=Step\\\\tail\\tline\\nend\\r");
+  EXPECT_EQ(FieldValue(fields, "force_correction_numerator"), "force_correction_numerator=not-evaluated");
+  EXPECT_EQ(FieldValue(fields, "force_increment_norm"), "force_increment_norm=0");
+  EXPECT_EQ(FieldValue(fields, "strict_residual_pass"), "strict_residual_pass=not-evaluated");
+  EXPECT_EQ(FieldValue(fields, "moment_correction_unit"), "moment_correction_unit=rad");
+  EXPECT_DOUBLE_EQ(std::stod(ValueAfterEquals(FieldValue(fields, "force_residual_numerator"))),
+                   *record.fields[0].residual_numerator);
+}
+
+TEST(DynamicFieldIterationLog, InvalidFieldEvidenceFailsWithoutWritingPartialRecord) {
+  TempDirectory directory{"field-v2-invalid"};
+  const auto path = directory.Path() / "log.txt";
+  for (int kind = 0; kind < 4; ++kind) {
+    SCOPED_TRACE(kind);
+    fesa::NewtonIterationLogWriter writer;
+    ASSERT_TRUE(writer.Open(path).IsOk());
+    auto record = CompleteDynamicRecord();
+    record.policy_id = "abaqus2025-field-on-fesa-v1";
+    ASSERT_TRUE(writer.Write(record).IsOk());
+    ASSERT_TRUE(writer.Flush().IsOk());
+    const auto prefix = ReadLogBytes(path);
+    if (kind == 0) record.fields[0].branch = "unknown";
+    if (kind == 1) record.fields[0].estimated_correction = std::numeric_limits<double>::infinity();
+    if (kind == 2) record.fields[1].residual_scale = -1;
+    if (kind == 3) record.policy_id = "unknown";
+    ExpectLogOutputFailure(writer.Write(record));
+    ExpectLogOutputFailure(writer.Flush());
+    EXPECT_EQ(ReadLogBytes(path), prefix);
+  }
+}
+
+// Independent strict consumer: production has a writer, no public log reader.
+bool ReadFieldV2(const std::string& bytes) {
+  if (bytes.empty() || bytes.back() != '\n' || bytes.find('\r') != std::string::npos ||
+      std::count(bytes.begin(), bytes.end(), '\n') != 1) return false;
+  std::map<std::string, std::string> values;
+  for (const auto& field : SplitTabs(bytes.substr(0, bytes.size() - 1))) {
+    const auto equal = field.find('=');
+    if (equal == std::string::npos || !values.emplace(field.substr(0, equal), field.substr(equal + 1)).second)
+      return false;
+  }
+  for (const auto* key : {"record", "schema", "policy_id", "step", "increment", "time", "iteration", "stage", "outcome", "failure_code", "field_pass", "accepted"})
+    if (!values.count(key)) return false;
+  if (values["record"] != "dynamic-newton-iteration" || values["schema"] != "hht-log-v2" ||
+      values["policy_id"] != "abaqus2025-field-on-fesa-v1") return false;
+  const auto numeric = [](const std::string& text, bool missing) {
+    if (missing && text == "not-evaluated") return true;
+    double value = 0;
+    const auto parsed = std::from_chars(text.data(), text.data() + text.size(), value);
+    return parsed.ec == std::errc{} && parsed.ptr == text.data() + text.size() && std::isfinite(value) && value >= 0;
+  };
+  const auto boolean = [](const std::string& text, bool missing) {
+    return text == "0" || text == "1" || (missing && text == "not-evaluated");
+  };
+  for (const auto* key : {"increment", "iteration"}) {
+    std::uint64_t value = 0;
+    const auto& text = values[key];
+    const auto parsed = std::from_chars(text.data(), text.data() + text.size(), value);
+    if (parsed.ec != std::errc{} || parsed.ptr != text.data() + text.size()) return false;
+  }
+  if (!numeric(values["time"], false) || !boolean(values["field_pass"], true) || !boolean(values["accepted"], false)) return false;
+  for (const auto* prefix : {"force_", "moment_"}) {
+    for (const auto* suffix : {"residual_numerator", "residual_scale", "spatial_flux", "time_average_flux", "correction_numerator", "increment_norm", "estimated_correction", "residual_threshold", "correction_threshold"}) {
+      const auto found = values.find(std::string(prefix) + suffix);
+      if (found == values.end() || !numeric(found->second, true)) return false;
+    }
+    for (const auto* suffix : {"residual_pass", "correction_pass", "field_pass"}) {
+      const auto found = values.find(std::string(prefix) + suffix);
+      if (found == values.end() || !boolean(found->second, true)) return false;
+    }
+    const auto branch = values.find(std::string(prefix) + "branch");
+    if (branch == values.end() || (branch->second != "normal" && branch->second != "zero-flux" &&
+        branch->second != "linear" && branch->second != "nonquadratic" && branch->second != "not-evaluated")) return false;
+    if (values[std::string(prefix) + "residual_unit"] != (std::string(prefix) == "force_" ? "force" : "moment") ||
+        values[std::string(prefix) + "correction_unit"] != (std::string(prefix) == "force_" ? "length" : "rad")) return false;
+  }
+  for (const auto& entry : values)
+    for (std::size_t i = 0; i < entry.second.size(); ++i)
+      if (entry.second[i] == '\\') {
+        if (++i == entry.second.size() || (entry.second[i] != '\\' && entry.second[i] != 't' && entry.second[i] != 'n' && entry.second[i] != 'r')) return false;
+      }
+  return true;
+}
+
+TEST(DynamicFieldIterationLog, IndependentReaderRejectsMalformedVersionedRecords) {
+  TempDirectory directory{"field-reader"};
+  const auto path = directory.Path() / "log.txt";
+  fesa::NewtonIterationLogWriter writer;
+  ASSERT_TRUE(writer.Open(path).IsOk());
+  auto record = CompleteDynamicRecord();
+  record.policy_id = "abaqus2025-field-on-fesa-v1";
+  ASSERT_TRUE(writer.Write(record).IsOk());
+  ASSERT_TRUE(writer.Close().IsOk());
+  const auto valid = ReadLogBytes(path);
+  ASSERT_TRUE(ReadFieldV2(valid));
+  const auto replaced = [&](const std::string& from, const std::string& to) {
+    auto text = valid;
+    const auto start = text.find(from);
+    EXPECT_NE(start, std::string::npos);
+    text.replace(start, from.size(), to);
+    return text;
+  };
+  EXPECT_FALSE(ReadFieldV2(replaced("schema=hht-log-v2", "schema=hht-log-v1")));
+  EXPECT_FALSE(ReadFieldV2(replaced("\tincrement=2", "\tincrement=-1")));
+  EXPECT_FALSE(ReadFieldV2(replaced("\ttime=0.25", "\ttime=nan")));
+  EXPECT_FALSE(ReadFieldV2(replaced("\ttime=0.25", "\ttime=inf")));
+  EXPECT_FALSE(ReadFieldV2(replaced("force_residual_numerator=not-evaluated", "force_residual_numerator=1junk")));
+  EXPECT_FALSE(ReadFieldV2(replaced("force_branch=not-evaluated", "force_branch=unknown")));
+  EXPECT_FALSE(ReadFieldV2(replaced("\tfield_pass=not-evaluated", "\tfield_pass=true")));
+  EXPECT_FALSE(ReadFieldV2(replaced("\tstep=", "\tstep=bad\\x")));
+  EXPECT_FALSE(ReadFieldV2(replaced("\taccepted=0", "\taccepted=0\taccepted=0")));
+  EXPECT_FALSE(ReadFieldV2(replaced("\tforce_increment_norm=not-evaluated", "")));
+}
+
 }  // namespace