Fix mass extraction + db close order + nan handling

- Journal now extracts p173 mass expression and writes _temp_mass.txt
- history.get_study_summary() called before history.close()
- Optuna nan rejection: fallback to INFEASIBLE_MASS penalty
- pyNastran warning 'nx 2512 not supported' is harmless (reads fine)

projects/hydrotech-beam/studies/01_doe_landscape/run_doe.py

@@ -255,6 +255,12 @@ def evaluate_trial(
         )
         history.export_csv()  # Live update CSV after each trial
 
+    # Optuna rejects nan — use INFEASIBLE_MASS as fallback
+    import math
+    if math.isnan(nx_result.mass):
+        logger.warning("Trial %d: mass is NaN (extraction failed), using penalty value", trial_num)
+        return INFEASIBLE_MASS
+
     return nx_result.mass
 
 
@@ -542,10 +548,10 @@ def run_study(args: argparse.Namespace) -> None:
     # Cleanup
     solver.close()
 
-    # Final history export + summary
-    history.close()
+    # Final history summary (before close!)
     hist_summary = history.get_study_summary(study_name)
     logger.info("History DB: %d total records across all studies", hist_summary["total"])
+    history.close()
 
 
 def _progress_callback(study: optuna.Study, trial: optuna.trial.FrozenTrial) -> None: