feat: Add optimization execution and live results overlay to canvas

Phase 2 - Execution Bridge:
- Update /start endpoint to fallback to generic runner when no study script exists
- Auto-detect model files (.prt, .sim) from 1_setup/model/ directory
- Pass atomizer_spec.json path to generic runner

Phase 3 - Live Monitoring & Results Overlay:
- Add ResultBadge component for displaying values on canvas nodes
- Extend schema with resultValue and isFeasible fields
- Update DesignVarNode, ObjectiveNode, ConstraintNode, ExtractorNode to show results
- Add Run/Stop buttons and Results toggle to SpecRenderer
- Poll /status endpoint every 3s and map best_trial values to nodes
- Show green/red badges for constraint feasibility

atomizer-dashboard/frontend/src/components/canvas/nodes/ResultBadge.tsx

@@ -0,0 +1,39 @@
+import { memo } from 'react';
+
+interface ResultBadgeProps {
+  value: number | string | null | undefined;
+  unit?: string;
+  isFeasible?: boolean; // For constraints
+  label?: string;
+}
+
+export const ResultBadge = memo(function ResultBadge({ value, unit, isFeasible, label }: ResultBadgeProps) {
+  if (value === null || value === undefined) return null;
+
+  const displayValue = typeof value === 'number' 
+    ? value.toLocaleString(undefined, { maximumFractionDigits: 4 }) 
+    : value;
+
+  // Determine color based on feasibility (if provided)
+  let bgColor = 'bg-primary-500/20';
+  let textColor = 'text-primary-300';
+  let borderColor = 'border-primary-500/30';
+
+  if (isFeasible === true) {
+    bgColor = 'bg-emerald-500/20';
+    textColor = 'text-emerald-300';
+    borderColor = 'border-emerald-500/30';
+  } else if (isFeasible === false) {
+    bgColor = 'bg-red-500/20';
+    textColor = 'text-red-300';
+    borderColor = 'border-red-500/30';
+  }
+
+  return (
+    <div className={`absolute -top-3 -right-2 px-2 py-0.5 rounded-full border ${bgColor} ${borderColor} ${textColor} text-xs font-mono shadow-lg backdrop-blur-sm z-10 flex items-center gap-1`}>
+      {label && <span className="opacity-70 mr-1">{label}:</span>}
+      <span className="font-bold">{displayValue}</span>
+      {unit && <span className="opacity-70 text-[10px] ml-0.5">{unit}</span>}
+    </div>
+  );
+});