fix: NX installation path detection for run-baseline endpoint

- Read nx_install_path from atomizer_spec.json if available
- Auto-detect from common Siemens installation paths
- Fixes issue where NX2512 wasn't found (actual path is DesigncenterNX2512)

atomizer-dashboard/backend/api/routes/optimization.py

@@ -4662,8 +4662,31 @@ async def run_baseline_simulation(study_id: str):
         # Try to run the solver
         try:
             from optimization_engine.nx.solver import NXSolver
+            from pathlib import Path as P
+
+            # Try to get NX settings from spec
+            spec_file = study_dir / "atomizer_spec.json"
+            nx_install_path = None
+            if spec_file.exists():
+                with open(spec_file) as f:
+                    spec_data = json.load(f)
+                nx_install_path = (
+                    spec_data.get("model", {}).get("nx_settings", {}).get("nx_install_path")
+                )
+
+            # Default to common installation path if not in spec
+            if not nx_install_path:
+                for candidate in [
+                    "C:/Program Files/Siemens/DesigncenterNX2512",
+                    "C:/Program Files/Siemens/NX2506",
+                    "C:/Program Files/Siemens/NX2412",
+                ]:
+                    if P(candidate).exists():
+                        nx_install_path = candidate
+                        break
 
             solver = NXSolver(
+                nx_install_dir=P(nx_install_path) if nx_install_path else None,
                 nastran_version="2512",
                 timeout=600,
                 use_journal=True,