feat(canvas): Add 'Run Baseline' FEA simulation feature to IntrospectionPanel

Backend:
- Add POST /api/optimization/studies/{study_id}/nx/run-baseline endpoint
- Creates trial_baseline folder in 2_iterations/
- Copies all model files and runs NXSolver
- Returns paths to result files (.op2, .f06, .bdf) for extractor testing

Frontend:
- Add 'Run Baseline Simulation' button to IntrospectionPanel
- Show progress spinner during simulation
- Display result files when complete (OP2, F06, BDF)
- Show error messages if simulation fails

This enables:
- Testing custom extractors against real FEA results
- Validating the simulation pipeline before optimization
- Inspecting boundary conditions and loads

atomizer-dashboard/frontend/src/components/canvas/panels/IntrospectionPanel.tsx

@@ -83,6 +83,23 @@ interface IntrospectionResult {
   linked_parts?: Record<string, unknown>;
 }
 
+// Baseline run result interface
+interface BaselineRunResult {
+  success: boolean;
+  study_id: string;
+  baseline_dir: string;
+  sim_file?: string;
+  elapsed_time?: number;
+  result_files?: {
+    op2: string[];
+    f06: string[];
+    bdf: string[];
+  };
+  errors?: string[];
+  error?: string;
+  message: string;
+}
+
 export function IntrospectionPanel({ filePath, studyId, onClose }: IntrospectionPanelProps) {
   const [result, setResult] = useState<IntrospectionResult | null>(null);
   const [isLoading, setIsLoading] = useState(false);
@@ -91,6 +108,10 @@ export function IntrospectionPanel({ filePath, studyId, onClose }: Introspection
     new Set(['expressions', 'extractors'])
   );
   const [searchTerm, setSearchTerm] = useState('');
+  
+  // Baseline run state
+  const [isRunningBaseline, setIsRunningBaseline] = useState(false);
+  const [baselineResult, setBaselineResult] = useState<BaselineRunResult | null>(null);
 
   const { addNode, nodes } = useCanvasStore();
 
@@ -136,6 +157,37 @@ export function IntrospectionPanel({ filePath, studyId, onClose }: Introspection
     runIntrospection();
   }, [runIntrospection]);
 
+  // Run baseline FEA simulation
+  const runBaseline = useCallback(async () => {
+    if (!studyId) {
+      setError('Study ID required to run baseline');
+      return;
+    }
+
+    setIsRunningBaseline(true);
+    setBaselineResult(null);
+    setError(null);
+    
+    try {
+      const res = await fetch(`/api/optimization/studies/${studyId}/nx/run-baseline`, {
+        method: 'POST',
+      });
+      
+      const data = await res.json();
+      setBaselineResult(data);
+      
+      if (!data.success && data.error) {
+        setError(`Baseline run failed: ${data.error}`);
+      }
+    } catch (e) {
+      const msg = e instanceof Error ? e.message : 'Failed to run baseline';
+      setError(msg);
+      console.error('Baseline run error:', e);
+    } finally {
+      setIsRunningBaseline(false);
+    }
+  }, [studyId]);
+
   const toggleSection = (section: string) => {
     setExpandedSections((prev) => {
       const next = new Set(prev);
@@ -243,6 +295,87 @@ export function IntrospectionPanel({ filePath, studyId, onClose }: Introspection
         />
       </div>
 
+      {/* Run Baseline Button */}
+      {studyId && (
+        <div className="px-4 py-2 border-b border-dark-700">
+          <button
+            onClick={runBaseline}
+            disabled={isRunningBaseline}
+            className="w-full flex items-center justify-center gap-2 px-3 py-2 
+                       bg-emerald-600 hover:bg-emerald-500 disabled:bg-dark-700 
+                       text-white disabled:text-dark-400 text-sm font-medium 
+                       rounded-lg transition-colors"
+          >
+            {isRunningBaseline ? (
+              <>
+                <RefreshCw size={14} className="animate-spin" />
+                Running Baseline FEA...
+              </>
+            ) : (
+              <>
+                <Cpu size={14} />
+                Run Baseline Simulation
+              </>
+            )}
+          </button>
+          <p className="text-xs text-dark-500 mt-1.5 text-center">
+            Creates result files (.op2, .f06) for testing extractors
+          </p>
+        </div>
+      )}
+
+      {/* Baseline Run Result */}
+      {baselineResult && (
+        <div className={`mx-2 my-2 p-3 rounded-lg border ${
+          baselineResult.success 
+            ? 'bg-emerald-500/10 border-emerald-500/30' 
+            : 'bg-red-500/10 border-red-500/30'
+        }`}>
+          <div className="flex items-center gap-2 mb-2">
+            {baselineResult.success ? (
+              <div className="w-2 h-2 rounded-full bg-emerald-400" />
+            ) : (
+              <AlertTriangle size={14} className="text-red-400" />
+            )}
+            <span className={`text-xs font-medium ${
+              baselineResult.success ? 'text-emerald-400' : 'text-red-400'
+            }`}>
+              {baselineResult.message}
+            </span>
+          </div>
+          
+          {baselineResult.elapsed_time && (
+            <p className="text-xs text-dark-400 mb-1">
+              Completed in {baselineResult.elapsed_time.toFixed(1)}s
+            </p>
+          )}
+          
+          {baselineResult.result_files && (
+            <div className="space-y-1">
+              {baselineResult.result_files.op2.length > 0 && (
+                <p className="text-xs text-dark-300">
+                  <span className="text-emerald-400">OP2:</span> {baselineResult.result_files.op2.join(', ')}
+                </p>
+              )}
+              {baselineResult.result_files.f06.length > 0 && (
+                <p className="text-xs text-dark-300">
+                  <span className="text-blue-400">F06:</span> {baselineResult.result_files.f06.join(', ')}
+                </p>
+              )}
+              {baselineResult.result_files.bdf.length > 0 && (
+                <p className="text-xs text-dark-300">
+                  <span className="text-amber-400">BDF:</span> {baselineResult.result_files.bdf.join(', ')}
+                </p>
+              )}
+            </div>
+          )}
+          
+          {baselineResult.error && (
+            <p className="text-xs text-red-400 mt-1">{baselineResult.error}</p>
+          )}
+        </div>
+      )}
+
       {/* Content */}
       <div className="flex-1 overflow-auto">
         {isLoading ? (